Here are the applications that I utilize most often on my Blackberry Storm:

UberTwitter: An awesome app for mobile Twitter.

Pandora: mobile Pandora is music to my ears.

Gmail: The Gmail app for the Blackberry Storm has the best scrolling of any app on the phone…it’s even better than the apps by RIM.

Slacker: Another web radio app, similar to Pandora.

Facebook: It’s mostly useful for reading status updates. Mobile Facebook via the Storm’s browser works well too.

Google Maps: Great for when you get lost or need directions. Uses the Storm’s GPS when it’s active.

Flickr: Take photos with your phone and upload them to your Flickr account.

YouTube: Watch your favorite YouTube videos on your phone.

BuzzMe: Runs in the background. Allows for your phone to both vibrate and ring during incoming calls.

Bonus: The wallpaper that’s currently on my Storm’s “home” screen.