Ok, here is my list. I tried to avoid repeating anything someone already mentioned. I was going to include screen shots too, but figured that would make this WAY too long.
Album Art Grabber (Perfect for those missing album covers)
Easy Money (The best money manager I have seen. Constant support from the dev too.)
GDocs (The best for quick down and dirty document viewing and editing)
iTag (2.1 only)(Unknown album or artist? Not anymore.)
Key Ring Rewards Card (The updates have made this a really solid and useful app)
MortPlayer Audio Books (Great free audio book player that allows for bookmarking)
Places Directory (Pretty much what it says. If you need a place, this can usually find it)
RadioTime (I dropped XM because of this app. Stations from around the world and right next door.)
Red Poker Club (If you like poker this is great for a quick multiplayer game anytime.)
Tone Picker (Use it to assign ringtones and notification tones to anything. Quick and easy.)
vizBattery Widget (Small sized battery widget that won't eat at your battery life.)
USAA Mobile (If you bank with them this is about the coolest app ever made. You can deposit checks into your account from your phone.)
White Noise Lite (If you need sounds to help you fall asleep this is a wonderful app.)
WPT