I only have free stuff on mine (ZTE Blade, got it last christmas for 114€ + 2€/month for 2 years for unlimited max speed internet):
Air Control Lite - Guide planes into runways. May sound meh but it's alot of fun.
aDownloader - Free torrent client
aTilt 3D Labyrinth - Once you disable the 3D bit it's a great balance-the-ball game, with LOTS of levels.
Battery Notifier - Shows the % of battery left as an icon, also plays a sound every x minutes if battery level is below y. I recorded the lowbat sound of my ancient nokia, works well
Classic Simon - Remember the game from Speden Spelit with the machine that has 4 buttons (red, green, yellow, blue) and you have to remember the order it plays them in? It's that.
Easy Installer - To install apps as apk's (aka not in the market)
ES File Explorer - Allows you to copy/paste stuff on your phone, or to/from shared folder on LAN or to/from ftp.
ES Task Manager - Quickly and easily close any apps that are running. aka ctrl+alt+del.
Mahjong - If you're into it.
Minesweeper Classic - Need I say more?
MixZing Basic - MP3 player, I picked this one after testing a few ones out. The playlist creation is a bit weird but it was the only mp3 player I found that could automatically create a playlist with all my songs sorted by album.
MoboPlayer - Plays pretty much any video format.
Moron Test: Section 1 - Lots of fun to watch friends play.
OliveOffice Premium - You can open, create, edit & save common office documents.
Opera Mini - It's so fast & works so quickly! The android browser easily makes my poor CPU cry, but I can have 13 tabs open in Opera, no problem.
OsmAnd - Completely free GPS/maps/navigation
with offline maps. It's nowhere near as fast as other map apps, but it's the only one I found that's free, has offline maps and has a search. Also navigation but don't trust on it. Absolutely awesome app when abroad.
Retro Radio - Can play streamed music, aka net radio.
Reversi Free - It's Reversi.
Scrambled Net - A very nice little puzzle game, I recommend you try it.
Solitaire - Also includes Spider & FreeCell!
Stopwatch & Timer - Durr yeah. I use it for cooking all the time.
Sudoku Free - Generates a new one each time, in various difficulties.
Trillian - All your IM's in one!
Unblock Me Free - 600-900 levels of unblocking blocks. Very enjoyable on the train to school/work.
YLE Areena - You know. ps this allows you to view Finland only content even if abroad.
Wow that list got long fast.
If you want "proper" Nokia text message & low bat sounds, I can send you them