The mp3 player! Not only does the Fascinate have one of the best looking/performing mp3 player interfaces of ALL cellphones but the sound quality is absolutely fantastic. I've owned many android phones including the Hero, Droid, Incredible, EVO and X. While all good phones in their own right, the one thing they had in common was a lackluster mp3 player (sound, interface). While I do love Android, I always had a tiny bit of iphone envy just from the fact that I always had to carry two devices for listening to music and making calls. Not any more, While I'm far from an audiophile, I can recognize a great sounding mp3 player and the Fascinate is indeed a great sounding mp3 player. Running my Sennheiser IE8's into it just plain sounds wonderful with a very attractive user interface to boot. I've finally been able to retire my Ipod touch and can carry around one device for all my needs. Now if the price of 32 gb micro sd cards would just come down things would be perfect. If you haven't already, I would highly suggest giving it a listen. You won't be disappointed.