I was on /r/ladyboners for a few minutes right now taking a look at what the women of reddit find sexy or attractive. I assume with 77,000 subscribers they represent the average taste in men.

What I noticed was a lot of different types of men. There are a lot of celebrities posted there but without a "cookie cutter" formula for a top post except for it being a white male. It wasn't until I got down to top post 109 that I found Obama on there but I suspect it was because he won the presidency that he got upvotes rather than his being sexy.

The poses these men are in are ones of power OR affection. If you go there, the upvoted pictures are where the man is flaunting his masculinity or when they have an inviting smile. The power pose has a clenched jaw and a piercing stare. The affectionate pose has a smile, preferable toothy (and usually with a pet) and is inviting.

I compare this with the top posts of /r/gentlemanboners (155,000 subscribers) where the majority of the poses are affectionate. They like the girl that smiles. The ones which were not smiling were still inviting, just strictly sexual. I guess this would be a woman's power pose but it's not the same power that the man exudes.

Conclusion, smile! It's sexy no matter who does it. If you are not smiling, pose yourself in a position of power. I think you guys talk about it in the side bar somewhere. I wrote this up on a whim, so feel free to add/scrutinize, we should learn something.