i've had two girlfriends for ~1.5 years (one of which I'm still good buds with).

Aside from that... hrm.... I suppose there was a girl in HS that was a couple years younger than me that I exchanged eyes with a few times that I entertained fantasies of actually talking to. Suppose that might have lasted a year or more. :dunno: When I was in elementary shcool I had a crush on Jessica Biel, before she made it obvious she was a raging kunt in training.

:edit: I guess when I was in college I'd get a new crush (or a few of them) every semester... but I'd either be attached (which was the case with the most promising [read: hot and not crazy] one) or too lacking in testicular fortitude to actually do something about it.