SwiftKey as already stated. Probably the best thing I have on there.
Beautiful Widgets - Customize that clock and weather to look good.
Flashlight - Should be a no brainer.
Flixter - Great for finding local theaters and movie times quickly.
Google Play Music - $7.50/month for unlimited music. It's like Pandora, but much much better. You can skip as much as you want, replay the song as many times as you like, make playlists, and if you are going on a flight, you can download the songs to your phone.
Bank App - Check to see if your bank has an app for you
TED - for watching all your TED Talks clips
aDownloader - For downloading torrents via mobile
Steam - Steam...
AndroIRC - IRC client
Convert Pad - Converts numbers into other numbers for around the world and measurements (C to F, $ to pounds etc)
Groupon - Save some dosh
Ingress - Google game that's pretty neat, check it out.
Meteor Blitz Free
Plague Inc. (awesome little game)
Sentinel3 - Best Tower Defense game imo on android
This is my home screen. Electric Plasma Live Wallpaper. Pretty rad.