[Otter]

I'm sure there's a big thread on programs you should get...But I'll still name a few:

Slide2Unlock - Nice locking program...Plus full-screen caller-id is neat.

Windows Live Search - Probably the best search program on Windows Mobile (It's free too). Search for businesses around you (either by text or voice). Find movies, movie theaters and their showtimes. And maps-directions....

Opera Mini - Fast browser. Full desktop -> Zoom in style with finger dragging.

Palringo - Great IM client; especially with the more recent updates, since they added preserved message chats. (Previously when you closed a chat, you would lose the conversation and it was a total pain to talk to multiple people, now it just stores in on the left soft-key and you can switch between people)

HTC Home Plugin - Does time, SMS/Phone Call/Email count, Program launching, Call person via thumbnail, Music player, and weather.

TCPMP + Flash Bundle - Allows you to stream videos from websites like YouTube. Plus TCPMP can stream internet radio streams (Windows Media Player can probably do this too...I just use TCPMP Full-time is all).

Those are probably my main programs.....But I'm sure there's more.