I don't know why, but the Brown Hair brown eyes has always been attractive to me. I also love Dirty blond with brown eyes, red hair with brown eyes. Either way brown eyes seems the most attractive to me.
I'm naturally light blond and have blue eyes, but I found that I love darker hair on myself and others with light blue eyes. I think the contrast of it is just so interesting. I don't really see many dark haired people with really light blue eyes. The only thing that's better is a deep chestnut brown with light green eyes (my ex-boyfriend's whole family had that combo and I was always jealous).