Interesting how many apps you end up accumulating. I've had an Android phone for less than a year and I'm out of space on my phone because I keep over 40 apps on it and Motorola has decided that 2.1 is the end of the line for the lowly Cliq :-P
List follows after the jump...
System Utility Apps:
Advanced Task Killer - I know you're not supposed to need to kill apps off, but the phone does lag when it has to spend a few moments to do this
EStrong File Manager - great for viewing files or deleting downloads
Google Places/Latitude/Voice/Skymap/Layar - Google experiments
Lookout - remote device location and wipe (somewhat redundant if you have a Motoblur phone but Motoblur causes lots of lagging)
FoxFi - tethering app that doesn't require root
Phone Info - lets you turn off 4G radio to save batteries
Data Management Apps:
aCar - car maintenance/mileage tracking
FlightView - track flight arrival/departure times
HeartPal - blood pressure tracking
iStockManager - TD Ameritrade's official app
Key Ring Reward Cards - so you don't have to carry all those stupid shopping discount cards with you all the time
Money Split - best tip calculator/splitter I've found where you only have to punch in the total bill
Pulse - one of the best RSS news readers
Square - process credit card transactions on your phone
Stock Alert - stock tracking app
ShopSavvy - barcode reader
SportsTracker (and Endomondo Sports Tracker) - track your workout and ties to a Zephyr's HxM bluetooth heart rate monitor
Torque - used with a bluetooth OBD-II reader to look at check engine codes and monitor car performance
WeatherBug - hourly weather forecasts
Zillow - real estate pricing info
Fring - unify all your IM and also does SIP outgoing calls
Programming Apps
aLogcat - display device logs w/o hooking it to Eclipse
androidVNC - VNC viewer
connectBot - SSH terminal
NeoRouter - client for Neorouter VPN solution
OSMonitor - show tasks and network state
PocketCloud - VNC/RDP viewer
Music:
3 (Cubed) - music player
Pandora - network music player that tunes channels to your preferences
Shazam - tells you what music is playing in your surrounding environment
Slacker - network music player w/ more variety
Food:
Epicurious - recipes
Urbanspoon - restaurant finder
Yelp - restaurant reviews
Entertainment:
Angry Birds Holidays - yep, I still don't understand why people like this game, but it works on the Cliq w/ 2.1
Armored Strike - my addictive game, but doesn't work on the Cliq w/ 2.1 because Motorola screwed up the update :-P
Fishin' 2 Go - when the weather is too crappy
DroidEmuLite - for those older SNES/GB/MAME games
Tank Recon 3D - battlezone like for the people that remember it
VirtualTenho - japanese mah jong game that's close to chinese style
USA TV Droid - local TV listings
Navigation:
Bluetooth GPS - in case you want a better GPS receiver than the built-in one
GPS Status - lots of info about the GPS receiver in your phone...lets you point at a satellite