Video Time Machine, from the guys behind YouTube Time Machine, is an awesome app that let's you select a year and category and then watch a relevant video. I've been enjoying all the videos of my youth.
There's categories like TV, Movies, Music, Ads, Video Games, Sports and others to watch, and the videos date back all the way back to 1860. The 10,000 videos in the app are curated so the selection is great but I wouldn't mind a bare bones search feature or at least, the ability to mark favorites. Even without that though, Video Time Machine serves as a really great cross section of pop culture over the years. I'm definitely going to lose hours to this. $1 [iTunes]