I wish people like DeanoG and airliebird58 would stop insisting people NEED to get Advanced Task Killer, unless they can tell us why killing apps is beneficial to the phone.
From all the reading I have done, and having gone from using ATK to deleting it all I can say is that programs load faster without ATK and the battery seems a little better too. Could be due to the fact that my commonly used programs are stored in my RAM (that uses the same amount of power whether full or empty - so where's the gain?) which means they don't have to screw the phone for power every time they are reopened.
Let Android handle memory and power, it actually seems very efficient.
I use it to kill apps that start to act weird, for example, i was typing something in the terminal, and the keyboard started to act weird(so i killed the terminal app, started it again and it worked)
i use "SystemPanel Lite" as a Task manager, not just task killer(i manage apps from that application) holding Home key pulls only last 8 apps used(some roms show more). this one lists all from ram, plus all the info about system(ram, cpu, device info, real time, and more)+it doesnt have ads. by holding the app in the list, you can switch to the app, kill it or see the info(how much ram, cpu, when it is started, and how it is running) this app does not have the notification icon(but you can add it with another app "Bar Control", you can add any app or shortcut to the notification bar with "Bar Control")
AndExplorer (file manager, simple, clean and easy to use, no ads)
Network Discovery (finds hosts on wifi network+port scanner)
DoubleTwist (music player)
arcMedia(video player, also it has support for subtitles if the subtitle is in srt. uses a lot of cpu if the file is big)
AppAware(find out what apps are people downloading, so that you can find some cool apps)
Barcode Scanner (scans for bar codes and qr codes, useful )
Google Goggles (everyone knows about this, the cool thing i found out is that you can take a picture in the papers of someone famous, and it will tell you who he is hehe, tried on a few politicians and musicians(does not work always)
FTPServer(i think this one requires root access) it makes an ftp server on your phone, i like it because i already use ftp client to access my websites, i just connect to the phone, so it is easier for me to transfer files over wifi, without connecting it to the cable, or using the bluetooth
Note Everything(notes app) + NE GDocs(it synchronizes with google docs, so that you cant lose your notes, they are in the cloud)
Any Cut (this app can make a shortcut to anything)
Paragon keyboard (it does not have any options, it cant vibrate, but i dont know, i type faster when i use it, i tried swype, but i suck at it)
it is not the games subforum, so i will just mention "Slice Slice" and "Graviturn"