Well for starters, I'll very often click on a profile because of what someone wrote in a forum or because his screen name implies common interests. But if you're just looking for what visually piques my interest, then generally it's (in no particular order but numbered for reference):
1. action shot in nature
2. general sports action shot
3. cool nature shot
4. something photographically different or odd
5. something showing him doing something I also love to do
6. just plain makes you say "whoa!" or "WTF?"
http://www.realjock.com/Thirdbeach (1, 3, 5)
I have never clicked on a torso shot unless it was overridden by interest in someone based on what he wrote. I find those utterly boring. If I like someone, I'll like his abs, whether they're washboard or washed up. But I won't _start_ liking him on account of them!