The must have rooted user apps.
1. Titanium Backup. For saving apps and there data plus a lot more.
2. Root Uninstaller. Saves all app apk's to folder on SD card. Apks versions can not be deleted by an update of app. Great if you get an update of an app and it's borked.
You can also pull apk's out of folder and put on root of SD card and install. Great for installing Titanium Backup after a fresh ROM install but no WiFi and slow 3G.
3. Root Browser light. The best free root file manager.
4. Kinetoo. Best antivirus app with the ability to scan not just apps, but all files on phone (need to be plugged in to charger as it takes as long as a full system scan on a regular computer).
5. LBE Privacy Guard. Control what permissions an app can have. Allow prompts if app wants to do anything.
You would be amazed at just what some of these apps can do. Make phone calls, edit contacts, etc.
6. ROM Manager. That's right, your not seeing things. As long as you don't use it to just flash a recovery to the V or download the 2 Gingerbread ROMs in the download list, then ROM Manager is a pretty amazing app. You can manage your backups (even rename them), backup current ROM ( name it, then it will back it up, then boot back to ROM), make automatic scheduled backups of ROM, and more. For more info check the All Things Root sub-forum stickies.
8. Fast reboot. The safest way to gain back RAM used by apps that don't need to be running.
9. Android System Info.
10. OS monitor.
11. Phone Explorer.
12. Periodic Auto Sync. Allows you to turn on Sync at scheduled intervals (saves battery juice).
13. AFV (Android File Verifier). Allows you to check the md5 sum of a download as well as generate one from a zip you created.
14. Clipbot. It allows you to save multiple copies to clipboard. I saved as many as 20 URL's (links to pics at Photo Bucket) and pasted all at once in a thread. Great when your helping someone in a thread and need to post multiple links..
15. SD Maid. For a real deep clean.
16. For those that need more space.....Link2SD.
For non rooted users and rooted users alike:
1. 3G Connection Fix Free.
2. Antennas. See where nearest tower is located.
3. GPS Status.
4. Network Tester. See if the network is really working and if it's connecting to the web.
5. outSSIDer. Use it to connect to any open network with just a push of a button. Instead of having to dig into system settings and selecting network, etc.
6. WiFi Radar. Home into an open WiFi signal. Gives you all WiFi signals, weather open or secure, and there direction relative to you.
7. WiFi analyzer. Gives you the strength, name, etc. of WiFi signals.
8. Password Book. Save passwords to sites with this password protected app.
9. TV.com. Works flawlessly on a WiFi connection to watch all sorts of CBS and The C W shows, Plus old shows like Star Trek, The Love Boat, Hawaii Five O, Dynasty, Family Ties, Perry Mason, etc.