I've listed most of these, but here you go again... for the noob owners.
Absolute Must Haves
AroundMe (Everything locater based on your current location)
OmniFocus (Organized my life. With Push)
Occasions (B-days(will pull Facebok info), Anniversaries, Holidays, anything reminder. With Push)
AwesomeNote (For notes. It's awesome)
TWC Max (weather)
What's On? (TV listings, reminders)
ESPN Scorecenter
Sportacular (Get Push updates for games. Updates every 10sec if you want)
MotionX GPS Drive (Turn by turn voice navigation. The shit.)
Flashlight (It's a flashlight.
)
WunderRadio (Streaming radio stations. AM and FM.)
Wikipanion
Convert
PdaNet (Tether to a computer for internet)
Jaadu RDP and Jaadu VNC (Remote connect to other computers)
Stanza (ebook reader)
Starmap Pro (Astronomy)
Games
Labyrinth 3D (Wooden marble game)
Trace (Very addictive simple game)
FlightControl (Air Traffic Control game)
Geared (Problem solving game using gears)
King Pin (Bowling Wii style)
Tiger Woods (expensive, but fun)