Aside from the base OS apps (calendar, camera, maps, calculator, notes, Safari), I've got my iPhone basically set to keep me as instantly informed and connected as possible with what I need.
HotSchedules (scheduling client for work)
Weather HD
RadarUS
Facebook
Facebook Messenger
Twitter
Yelp
ESPN ScoreCenter
ESPN Radio
Chicago Tribune
CNN
Pandora
Q101
TuneIn Radio
Cor.kz
Tapatalk
iMapMyRIDE+
GasBuddy
RedLaser
Amazon
Best Buy
eBay
iBooks
Dictionary.com
Google Translate
PNC Mobile
My Verizon
Capital One
Starbucks
And then when I'm bored, I have some good games.
Words with Friends (LOVE Words!!)
Solitaire
Blackjack
Jack or Better Video Poker
WSOP
Flick Golf
Flick Soccer
Angry Birds
Cut the Rope
That being said, I haven't sat down on a desktop computer in almost 5 months outside of the office because I have zero need to.