I've really enjoyed this thread.
My top apps (in no particular order):
-NFC Task Launcher (NFC tag reader/writer)
-Cheezeburger (Meme viewer)
-Google Reader (Blog reader)
-Google Drive (Online documents)
-Spotify (Internet radio)
-Sat Track (satellite tracker)
These are probably the apps I use the most. They are functional for me, not just novelty.