My view is it's a bit what you're used to! I understand that the vast majority of north american men are circumcised. On the other hand, very few british men are, except jewish guys of course and maybe muslims too I think? So british girls tend to think that circumsised ones look and feel wrong. Not sure what it's like in the rest of europe.
Foreskins are really odd things though -- taking them off removes a lot of the variety. Some blokes have really big foreskins, like humungous turtle-neck sweaters, and others have sort of unobtrusive ones, that kind of let the penis look more or less like it is circumcised.
There is a fantastic video I saw once called "dick" which is basically 30 minutes of snapshots of about 1000 penises. The variety is truly astonishing.