I generally don't use too many Apps on my Droid as the OS is very slow, way under powered - MyTouch - I'm on my second phone, think the phone is a POS.
Cherry R Player - Amazing, streaming music Icecast, Shoutcast..ect Blows any music app out of the water, I thought Pandora was good, I never get buffering issues and there are literally thousands of music stations.
Spare Parts
Spare Parts allow you to enable some of the settings that are not found in the default setting menu. So sum it up you can speed the animation on your phone, it helps with my slow OS.
Chase Bank
Visual Voicemail