I don't have ten, but I do have a few that haven't been mentioned.
LOCALE -- Wonderful wonderful. I have it silence my phone and turn down the screen brightness when I go to work/rehearsal. Those are based on appointments on my calendar. At night, Locale turns my ringer down so I don't have to worry about phonecalls while I sleep! You can change settings based on calendar events, contact calling, time & day, battery status, and even location. The only caveat is that if your phone looses location information, even for a minute, Locale reacts accordingly, switching you to defaults. It is nice, though, because the situations I have set up usually have WiFi turned off, so if I forget to turn it off myself, Locale will turn it off when the situation change happens.
ASETTINGS -- Simple, easy, one-page settings toggle.
MEMORYFORLEMMINGS -- When my G1 seems to be slowing down I just run this app real quick and everything is back up to speed again. Simple, free, legit.
WEATHERBUG -- Great UI and more information than you actually need, but comes in very handy. Especially like how it will show you video feeds from a camera nearby so that you can actually see what the weather is like before you go out into it.
ABLOGGER -- App that connects to blogger, way easier than trying to use the web-browser. Needs some improvements, but it's in it's pre-release stage right now, for testing and feedback, so there are definite plans to improve it.
OBAMA -- I voted for him, so it's nice to be able to keep track of what he's up to with this app.
ANYCUT, BETTERBOOKMARKS, BOOKMARKS2 -- Separately they provide extra functionality, but together they make a nice little suite for customizing your home screen with web (and other) links.