Here are my Top 5 Favorite Blackberry Apps:
1. Google Voice – Get your own number along with powerful communication tools.
2. UberTwitter – Full featured Twitter client. Beats the official Twitter App.
3. WordPress – Keep your Blog updated with this very high quality, well designed App
4. crunchSMS – Awesome SMS interface with bubbles.
5. Evernote – Access text, photos and audio creations from anywhere!
To download visit the Blackberry App World