http://tvtropes.org/pmwiki/pmwiki.php/M ... tlessScene
Although I prefer backs to chests. Muscled backs. They're very nice.
Also, long-haired pretty boys! Boys in fabulously frilly clothing, goth or renfaire or visual kei, it's all good...
Lingering focus on soulful eyes.
Style. I don't mean that in the sense of fashion, so much as... charisma. Some guys (and some characters) are just overflowing with awesome, so much so that
http://tvtropes.org/pmwiki/pmwiki.php/M ... uysWantHim I've seen a certain actor who I won't name, who has a huge following but who is EVEN SEXIER out of character, filmed in the audience of a new years eve gathering, just casual, relaxing in blue jeans and grinning with casual confidence and GAH sex on a stick.
But if you're looking for specifically more fanservicey moments within a story? A lot of girls go all swoony if a guy acts protective, especially if he can manage to pull it off without coming across like he's patronising or thinking of the girl as a helpless ninny. Trip and start to fall, hot guy catches you, doesn't tease you about it, grins at you, goes on his way... girl watches him leave, starry-eyed. Guy who's been working for the main villain all this time refuses to harm a hair on girl's head, and in fact stands in front of her and declares that anyone who wants to hurt her has to go through him? SWOON.
Alternately, a lot of girls are turned on by the idea of hidden danger, particularly a danger that *only they* can tame with the power of their luuuuuv (be careful with this one, it can lead to Twilight). Or, relatedly, the idea that the guy finds the girl so hot that he can't control himself. That's a power trip.
Yaoi-tease. The guys don't have to actually snog to play with fangirl attentions. Watch the twins in Host Club! Just the way they interact with each other is enough to reduce hordes to squee. A little bit of teasing flirtation between male characters, even if they don't mean it, will be fanservice enough to make many girls very happy.
There may not be quite a direct equivalent to the banana-eating, although licking ice cream gets that effect for some people. There's also a reason the phrase "he's good with his hands" is said in a suggestive manner! Demonstrating a firm-but-delicate touch, patience, creativity... generally suggesting he would be awesome in bed. Dancing can do that too.
But it's difficult because most people here know what they personally like and that's going to override more geenralised stuff in their requests. Guys are not homogenous either, but they tend to be more aware of what the generic-stuff-for-guys is supposed to be. (There are TONS of men who do not like big breasts. There are many men who do not like girls kissing girls. Etc.)
Also, in video games (not VNs so much but games in general) a lot of developers aren't willing to take even the first and simplest step towards fanservice - attractive male faces! At least Hollywood sometimes caters to women THAT much, even if they generally disdain the female audience...