it depends on the individual guy. nice, natural muscles are can be good on a guy, but i wouldn't necessarily not be attracted to a guy because he didn't have muscles. of course, if he looks like a steroid using bodybuilder, then that is really unattractive.

a guy's body type isn't really that big of a factor for me. i've liked skinny guys, medium, and slightly chubby. the only thing i don't do is fatties lol (no offense)