To me the whole point of rooting was to be able to control things I was restricted from managing myself before. Here is what I use for that:
Autorun Manager (free) and
Autostarts ($1.03) - both of these prevent programs from starting when your phone boots and hanging open. for those coming from windows, sort of like managing startup and services in msconfig.
Gemini App Manager (free) - love this app. i use it with the
Gemini Task Killer Widget to kill running tasks. You can set apps to never kill and then quickly hit the widget and kill everything else that is open. This is a manual task killer - by not autokilling it does not suck up valuable battery. You can also control autostarts from this app.
Gemini Installer and Clear (free) - can be used as an install manager, but i use the mostly as a cache clearing utility (there is a widget built in for this as well)
Ad Free Android (free) - sure, you can mod your own hosts file, but this is a nice easy way and since I travel a lot I can update on the fly. Life without ads is nice!
Avast Mobile Security (free) - everyone has their opinion on whether an antivirus is necessary for the Android OS. Forget that for a moment and focus on the firewall here. You can lock apps out of communication, so NO ADS in apps like Angry Birds! You can also lock out all apps while roaming, thus avoiding those pesky $10k bills that are always in the news. Another nice feature is the antitheft capabilities and the ability to schedule antivirus scans. Its also uses a small memory footprint (3-5mb).
ES File Explorer (free) - allowed me to remove or rename apps i did not want/need/use and manage the entire android file system.
The best part is on this whole list - you will spend a buck.