I'm very new to android. I was a vigorous power user on Iphone via jailbreak and mods. Having that out of the way I will list some apps that I have found very beneficial and works well with the LG Thrill. If im posting this in the wrong spot ADMIN please feel free to move this post to its proper place. The following is by no means the best apps to have but I have found good success thus far
Autokiller Memory Optimizer
Works well to keep memory and resources consumption to a minimum. I have not figured how to use the auto app kill features though. Good to save on battery life if used properly.
SetCPU
App clocks your cpu based on cretin condition of your phone. I have mine set to down clock based on how low the battery gets. Great for longer battery life.
Titanium backup
An obvious great app. Backup and restore
Go launcher EX
Launcher. Replace your phones stock launcher. Works without deleting anything so no worries about loosing stuff. Great platform to customize and tailor your phone to your taste.
Root Explorer
File manager akin to a standard tree file directory service. Handy to delete or move pesky files that get lost.
AddFree Android
Self explanatory. Cuts down the adds that get on your phone. Not perfect but way better than nothing.
Battery Widget
Looks simple but very a robust battery tool. Can tell you battery life in time left, temp, memory storage, and even has a battery consumption graph so when you think your phone hates you cause you battery dropped 50% in 1 hour you can figure out what happened.
That's all the useful info I got. Hope it helps someone.