I've been using a lot of them, but I have to go with using the earbuds that came with it to make a phone call. I cannot stand the phone quality of almost every phone I use (especially those junk ones at work), and it's a lot easier when you have audio in both ears and don't have to hold that darn thing up to your ear. I consider this quite amazing since the one thing I was worried about was phone call quality. Others that I would give honorable mention to are Google Maps, Mail, Alarm, and a Web App I found called "Miles" in which I can store fill-up info on my car. I seriously love the air-raid siren that is the "alarm" ringtone, which I use for the alarms.