I'm surprised no one has brought up the "Women are from Venus, Men are from Mars" stuff. From the (gay) sidelines here, I have long wondered about the general compatibility of men and women beyond sex. It's a running theme in entertainment -- and real life -- that men and women can be different to the point of routinely annoying the hell out of each other. Stereotype: women like to shop and talk about feelings/relationships, guys want to go fishing and hang out with the guys. Some of my straight male friends would prefer to never be in the company of a female he isn't fucking at the moment. Others, however, are emotionally bound with their girlfriends and wives, who are also their best friends. Sadly, I find that to be the exception.
It's the constant paradox. So many straight men prefer the company of other men, regardless of sexual orientation, in nearly all situations except when it comes to sex. I've always considered it a cruel joke of the universe that for so many straight men the one the want to be with is another guy but the one they are sexually aroused by is a woman.
A related question is whether gay men and straight women are generally more (nonsexually) compatible than straight men and straight women. It may have some basis in a simple fact -- when I interact with females, there's no sexual component for me; any impressions I have are completely about the personality and the professional/athletic/artistic skills. And I generally love women who love men.