Droidbox pro (a dropbox client that came out months before the official one, and still seems better)
Jewellust (a bejeweled clone)
BeyondPod (a podcatcher. I have stopped using this since I realised it was trashing filenames)
Reddit is fun (because the author deserved my $1)
Other than BeyondPod, I recommend these paid-for apps. BeyondPod may have fixed my bug, I haven’t checked.
The other 50 or so apps I have are free. I am very much hoping that froyo (android 2.2) comes to the motorola milestone so that I can install apps to the sd card – I keep running out of internal memory!