[originalsnuffy]

Slingplayer (as modified to play over 3g).

Need that CNBC fix in the am.

Orb, Slacker, and Pandora are pretty cool too.

 

[Kobra]

Spotify

 

[jaszypoo]

Last.fm Radio, VLC Remote, iAmpremote (or something like that, for winamp)

Bejeweled (2?) for the commute.

 

[Young Spade]

I would love a custom EQ app to be made for the store.

 

[majid]

The one I use most is Things (a to-do list manager that syncs with the desktop version of the app on Mac), but the one I like most is the official HP-15C calculator emulator, even though it is very pricey.

 

[stang]

Probably "Free Battery"

 

[Uncle Erik]

Hewlett Packard's 12C emulator.

Among other things, I am an accountant and the 12C is my favorite calculator. I have two and always keep one on my desk and another in a briefcase.

Unfortunately, it isn't convenient to pocket a 12C to take everywhere. However, having a 12C on the iPhone is a dream (a geeky dream, for sure) come true.

I still prefer a real 12C for crunching numbers, but a virtual one is almost as good.

 

[Kobra]

I've just changed my mind about my favorite app, it's not an app per se but… blackra1n

It has given me a completely new iPhone with so much more functionality than it had before. It's really easy to use and it will not affect your warranty.