I've been installing quite a few apps since I bought the phone.
I turn on Waze while I drive to work. It's a great app, but will become even better as more people start using it.
Some of the tools I've been using are Wifi Analyzer, Folder Organizer, the HTC flashlight, Soundhound, Barcode Scanner, Google Sky, JuiceDefender, Where's My Droid, RemoteView, Convertr, Point Inside, Lookout, and Qik.
As far games go, the ones I come back to are Battleheart, all the games made my Creative Mobile, Snes9x EX, Pocket Legends, Naval Clash, Chess.com's app, and lastly the phenomenal Amazon Store which offers up a bit of everything.
For productivity, I have Catch Notes, Days Left, and all of the Google cloud apps.
My multimedia apps include TuneWiki, Pandora, Free MP3 Downloads from G-tunes Mobi, Pandora and Soundhound. The European music streaming service (I forget what it's called) doesn't support Android yet, but I'm probably going to try that out.
I've tried the other keyboards, but the HTC keyboard is probably the best. There is one problem with it though. The Swype functionality doesn't work in all the input areas, but I think that the size of the keyboard and the accuracy and speed of the trace function makes it better than Skype.
A lot of the apps I've picked up through reading the forums which is probably the best app of them all
