Firstly, get yourself on appbrain
and install their app. This will allow you to search for apps online and then install them later on your phone.Quick settings
is a must for easy access to all commonly used settings.App Aware
tells you what those around you are installing/uninstalling. Good for discovering new apps.Shazam
for finding out what that track is that is currently playing.Task Manager
good to help with killing apps and automatically killing them in the background (have read reports though that this isn't really necessary-but I find it does no harm)Unit converterCurrency converterCalvin and Hobbes!DGAway
pops up with a little screen of auto text options after you reject a callHandcent SMS
must have sms applicationSMS Backup
backs up your SMSs to your Gmail accountSubstrate Live Wallpapers
not sure if your device is capable, but this collection of live wallpapers is pretty coolWaveSecure Mobile Security
as their site says "Remotely locate your phone, track SIM, lock, backup, wipe & restore data"
I am constantly installing things to check them out, with this if you fire up the app and it sucks just shake the phone and an automatic uninstall options comes up.