The modest cuteness of the the girl in the last picture was more appealing. 😀
That, and you can tell its an actual picture with no props which makes it seem more natural and realistic and something that just happened spur of the moment, which makes it more fun to look at. The girl in #2 was obviously preped for that. Which means the person who took the picture assumes to know what sexiness is for all men in all cases- less clothing.
The girl in #5 didn't need any of this and she's the only photo that doesn't seem staged in order to give people what they think they'll want to see (poses etc.) #5 is all natural, and that "girl-next-door" look is far too underestimated. In reality, I think the majority of men would want to settle down with #5 anyway. #2 looks too high maintainance, and like she was paid to take the picture and wouldn't have done it otherwise. She looks almost apprehensive. You can tell #5 didn't mind, and she has this bright smile of approval almost. She seems like a fun girl.
But maybe thats just what I think 😛 LOL ^__^
EDIT:
After looking at the picture again, I noticed #5 has had a breast job done. That doesn't help for me, as they don't look good on her that big I think, but its still #5 for me.