I've only been in one ~serious~ relationship and he was almost 2 years older than me. I also dated a guy for ONE DAY (lol long story) and he was 7 years older than me.
But the two guys I have massive crushes on right now are both younger than me. The one with any potential of something happening is only 17 (I'm 20), and the other, my really sexy neighbour, is 18, but I think taken, or at least out of my league.