Apps I use frequently:

BeejiveIM - Decent IM client with push support
Gowalla - Location based game, similar to Foursquare
Mint.com - Financial program that integrates with the web site
BBCReader - Nice BBC news app, includes offline mode
Sim City - Has a feeling somewhere between 2000 and 3, been slowly building out a city
Peggle - Wishing they had Peggle nights out as well
Tile Poker - Fun little Poker meets Bejeweled type game, made by a former artist coworker

Oh, and i.wund.com is a site I use for weather, added it as a bookmark on my home page. Really handy for the wundermap to see the next major hailstorm coming into the area.