I voted European, but in general foreign girls > US girls. (I'm guessing that you mean american as in USA right? cuz USA girls can't hold a candle to latin american women).
They have personality, lot less mental issues, and are generally more there.
Looks wise; even the slightly heavier girls in europe carry themselves well. they dress nicer, are more fit (they can walk without being winded, omg!). The pretty ones are in general cooler than their usa counterparts.
I've dated pretty us girls... they all (ok, most) had issues and (in some cases, severe) baggage. haven't dated a slightly thick us girl - they seem intent on wearing sweats or tight shirts that expose their ever expanding gut. have dated thin and slightly thick european girls.
but hey, maybe it's just the girls that i go out with and the environment i was brought up.
but hey, everyone's experiences are going to be different.