When I'm out with friends in pubs/clubs that one of the boys goes home with a different good looking girl every week. He's 6'3", lean 16st, tanned, looks like Gerald Buttler and is very confident (trust me he's HOT haha). My other mate's not a good looking guy but he's got a gorgeous girlfriend. Another friend, is chissel jawed, in good shape but socially backward and I'm not even sure he's kissed a girl.
I'd say I'm average looking (at best), but both my girlfriends have been very pretty (my mates reminded me they were out of my league often enough haha).

So as someone else said 'beauty is in the eye of the beholder', but there are things you can do to make yourself more 'attractive'. In my case I'm assuming my naturally cocky funny attitude made me more 'attractive'.

P.S. I'm new to pick up, this just my exeprience, so take it with a pince of salt.