Never played Amped 1 or 2, as I don't really like trickstyle games normally. Picked up Amped 3 used on a whim and have to say I LOVE it. While it may not be 'next gen' in visuals, the hi-def makes it nice and crisp and easy on the eyes. I like the open style of gameplay and medal system....and loved most of the story mode (one or two cutscenes didn't make the grade but many I found most amusing). I like the variety in the soundtrack, opening up lots of new items etc. Easily one of my most loved 360 games and I've got most of the well regarded titles apart from any sports stuff.
Anyhow, for me, Amped 3 was a great surprise...and I've finally found a trickstyle game I enjoy. Now, off to get some more GOLD medals, I need to get up them there leaderboards.