Amazon: Amazon's usually the first place I look during a fit of impulse buying, which their iPhone app now makes stupidly easy.
Product searches, comparisons and account management are a given, but what really pushes this one over the edge is a new feature called "Remembers." Just snap a picture of a mysterious product or thing, and Amazon will get back to you with a surprisingly accurate, impressively quick suggestion as to what it is. Then it will sell said thing to you. Magic.
AOL Radio: More free radio content than any actual radio could ever have. Tailored radio stations are great, sure, but old-fashioned programmed stations-AOL Radio's specialty-have their charms.
Chorus: You know the App Store needs an overhaul when apps like Chorus, which help you find other apps, are necessary. But alas, they are.
Chorus crowdsources the effort to cut through the endless jungle of trash. Chorus is a bit like Apple's native App Store app, except with drastically shifted emphasis: instead of giving category "Top" lists, which rank apps by overall download numbers, Chorus only pitches you apps that've been explicitly recommended by someone. These someones could include other friends who use Chorus, nearby Chorus users, or a stable of "App Mavens"-online reviewers and tech journalists, mostly.
Dragon Dictation: Amazingly accurate dictation software that usually costs (multiple!) dollars elsewhere, Dragon Dictation brings the best speech recognition engine on the market to your iPhone. It's free, but probably not forever, so go go go.
Dropbox: Keeps selected files in sync between your iPhone, computer, and online account with almost no effort. 2GB of online storage comes free.
Dictionary: The best dictionaries on the iPhone are paid, but let's be honest, who pays for a dictionary nowadays?
Epicurious: The only cooking app you really need. With its thousands of recipes, shopping list feature and meal suggestions, Epicurious will make you at least look like a passable cook.
Echofon: What it lacks in bells and whistles, Echofon more than makes up for where it counts, at least for most: It's as quick as Twitter apps get, and caches Tweets, so you can read them later on without a connection. It doesn't support multiple accounts, but most reasonable people don't need that.
Evernote: Obsessive documenters, take note(s): This is the only scribbling app you need. There's a paid version too, but you get an awful lot for free.
Anything you need to jot down fast, be it in text, a photo, or a voice note, Evernote will keep it, index it, and sync it to Evernote's online subscription service. Where Evernote trumps all others, aside from its fantastic syncing abilities, is with search: You can sort your notes by all kind of parameters, and it never take more than a few seconds to find one.
Facebook: This was an essential app from the get-go, and it's been steadily evolving-like the site-for the last year. Version 3.0 was a total refresh, and supports nearly every one of Facebook's sprawling features, sometimes better than the site itself.
The new, panel-based interface takes a little getting used to, but once you're acclimated to it it's the most effective way to throw yourself, fingers first, into the black hole timesuck that is Facebook.
Fring: Every major instant message protocol, comfortably crowded under one (free!) roof. The addition of push notifications notched this one up from great to, uh, greaterer.
Obviously Skype is still your safest bet for making Skype calls, but Fring can do it passably well, too. Most people were excited for push notifications precisely because of how they could used for instant messaging, and Fring more or less fulfills this vision for free.
Google Mobile: Google Mobile was a solid app (but not particularly essential)-and then came voice search.
It's a natural thing for a cellphone-tap a button, say what you want, and there it is. You can search the web, local results-everything the Google app could previously do.
Google Earth: The same amazing Earth touring app found on the desktop, now spinnable via multitouch. Honestly if someone told me two years ago I would have a functional Google Earth app on my phone, I wouldn't have believed them. This is now.
IMDB: Every movie, every show, every actor, every bit of insignificant trivia: It's all here, in the IMDB app. It'll do local movie and TV listings as well, which is a nice bonus.
Instapaper Free: Yanks a carbon copy of any website into local storage for later reading on the subway, plane, or other place where AT&T service doesn't reach, like, oh, San Francisco, or New York.
Layar: Layar, the first camera-based AR app to really blow us (or anyone) away, has quietly slipped into the App Store. As with the Android version, the app overlays all kinds of information onto a live view of the world around you.
Layar layers, which let you install user-generated overlays of all different kinds of information, like this one, which tracks government bailout spending. The expansion possibilities here are huge.
Lockbox: An encrypted, safe place to stash all your secret or sensitive information. It's like a really good friend, except it will never ever ever betray you, because it has no free will. Genius!
Last.fm: Creates free, effectively endless custom radio stations, streams them over 3G and learns more about your musical tastes with time. There is literally no downside to this app.
This one is a bit more of a companion app than the other radio services, in that it's accompanied by fantastic desktop clients, a rich website and plugins for Audioscrobbler-its recommendation system-for pretty much any music player out there. As far as the music goes, though, you're bound to find some new stuff here, especially if you don't mind more eclectic tunes.
OpenTable: Actually talking to a maître d' on the phone: Out. Tapping your iPhone a few times to get a dinner reservation at a veritable assload of restaurants: In.
Just like its namesake website, OpenTable gloms together a healthy mix of restaurant listings, contact info and reviews, with an all-important reservation feature, which is literally the most painless, passive, shut-in-friendly way to get a table for
the anniversary of your pet fish's death
PanoLab: Who knew multitouch is the perfect interface for stitching photos together into panoramas? It is. Plus if the photo you just took doesn't work, toss it out and take another one immediately. A paid version adds even more features, but the free version do well enough for most panoramas.
Pageonce Personal Assistant: Are you a fancy businessperson, with "accounts" and "subscriptions" and, uh, "dollars?" Personal Assistant sucks your scattered financial, travel and leisure concerns all into one simple, unscary interface.
I've got the organizational skills of a drunk five-year-old, so I can't even put a price on the ability to keep my bank account, phone bill, Netflix account and pretty much everything else that has a recurrent billing component in one app, with bonus idiot-simple graphs and balance charts. It makes being an adult easier, and as a bonus, gives you an excuse to refer to your "personal assistant" in public. Extra props for the barely-crippled free version, which is immensely useful.
Pandora: Best internet radio app, hands down. Smartly auto-suggests music based on other artists you like. Both on the go and while at home. Streams well over EDGE and 3G. Free. What more could you ask for?
Photoshop: This app bears almost no resemblance to the Photoshop we all know and love and steal, always. That's fine though, because it's a serviceable photo-editing (on the iPhone, this means filters, cropping, and a few other tricks) app that is free, unlike virtually all of its competition.
RSS Runner: NetNewsWire was the old choice for best free newsreader, but it's gotten so buggy and slow as of late that it's time to recommend something a little leaner. RSS Runner diligently slurps news stories from your feeds, just like you want it to. That is all.
Skype: On 3G, it's perfect for Skype messaging and long distance texts; on Wi-Fi, it near-magically turns your iPhone into a VoIP handset.
Given that you can't make VoIP calls unless you're connected to Wi-Fi, Skype is surprisingly useful: even if you're tethered to your router's range, having a phone-shaped tool to make Skype calls is really nice, and its messaging service is a solid, not to mention fairly ubiquitous, way to keep in touch with people. Note: This one ceases to be free if you use SkypeOut, but that's pretty hard to do by accident, since you've got to buy credit for it to even work.
ShopSavvy: This is one of the best barcode apps for Android, and now it's available on the iPhone.
Early reviews were a bit harsh, since the app works better with the 3GS (autofocus, y'know?) and the scanning libraries needed some work. At any rate, it's free, works well for most people and the data-even if it can be sparse on some local searches-is invaluable.
Slacker Radio: Yet another free, customizable radio app, but one that has a spectacularly huge music library, and that gives you fine control over the songs you hear.
Slacker is pitted directly against Pandora, and they do a lot of similar things. Enter an artist or term to create a new radio station, though, and they'll give you totally different, but equally awesome, streams of music. And hey, they're free, so why not use both?
Stanza: A free ereader with a decent paid store, and more importantly (for cheapskates), a massive free library.
Stitcher: Collects and stitches together spoken word radio content from a healthy range of news and opinion sources, creating an effectively unlimited stream of stuff to listen to. Think of it as your local public radio station, times 400.
Sugarsync: A file storage and syncing app a bit like Air Sharing, except, you know, it doesn't cost anything. It depends on cloud storage, but you get 2GB of that for free.
TED: The TED conference is the yearly gathering for the world's best minds, many of whom are more than happy to speak, at length, about what they're thinking, doing, and dreaming. The TED app gives you more of these lectures that you'll ever have time to sit through, in a variety of formats.
VNC Lite: View and fully control my computer from anywhere, as long as I am on the same network. So I can basically be at my computer without actually being at my computer.
Waze: Free, crowd-sourced turn-by-turn app Waze might not navigate quite as well as the Navigons and Telenavs of the world, but it's got one killer feature that they don't: Pac-man mode.
The crowd-sourced data works well in some areas now, and the more people use it, the better it'll get. For now though, it's by far the most capable free turn-by-turn app on the iPhone.
Wikipanion: Why even carry an iPhone if you can't use it to settle petty arguments about things that don't matter?
A mercifully non-literal mobile translation of Wikpedia's interface, Wikipanion gets you to whatever 'pedia article you're looking for a few seconds faster than the regular browser would, and with much kinder navigation once you get there.
Yelp: Yelp is built on the premise that people really, really love to review things, and that this bizarre impulse should be harnessed for good. With a massive database of food/drink/everything else reviews, easy navigation, inbuilt maps, and augmented reality, it's tops.