Androidify: The Androidify app lets you make a "you" version of the Android bot, for avatar pics on Twitter, Facebook or your dating profile. Free.
PlayOn: PlayOn is the snazzy service that can stream online video content like Netflix, Hulu, ESPN, Comedy Central, etc. to other devices, in this case your Android phone (2.2+). You need to install some software on your PC (it's PC-only too) and it requires a $40/year subscription (but does come with a 14-day free trial).
MapQuest: Android users now have the luxury of another free turn-by-turn option to choose from- Mappquest's free voice-guided nav app is now available in the Android Market. You can talk to it (search for destinations with voice); it can talk to you (it'll pipe up when you need to make a turn); and it has live traffic data refreshed every five minutes.
Sleep as an Droid: It's a smarter, more considerate alarm clock. It's smarter because the app can track your sleep cycle and patterns: when you're in light sleep, when you're in deep sleep and so on. It's more considerate because the idea is to wake you up gently, with a soft ascending alarm, when you're in a period of "light sleep". That way you're happier and have more energy to start the day.
Tap-Translate: Tap-Translate is a new app (or really, a bookmarklet posing as an app) that translates words in foreign languages right from your phone's browser. No exiting the app, no switching, no fuss. That means whenever you stumble upon something you don't understand you just click on the bookmark, tap on the questionable word and let it translate. The app can display the word, say the word out loud and even translate the entire page.
Words with Friends: It took forever, but Words With Friends, the Scrabble clone, finally gets to Android. If your iPhone-having friends haven't ditched the game already, like mine have, you can do some cross-platform word-making.