As a gay gamer, I have to respectfully disagree on some of the male champions you called out as underdressed but non-sexualized. I think given roughly the same amount of clothing/skin ratio, the degree of sexualization is not something entirely in the hands of the developer or artist, but also the disposition of the audience. Basically, I'm saying that you appear to be dismissing Tryndamere, Varus, Lee Sin, Penta Olaf, and Pantheon as under-sexualized because you don't find them sexy. Bodybuilders are 'nasty'? That's an entirely subjective statement and you went on to turn it into a blanket generalization. I happen to find bulky-built men incredibly sexy. For me, Tryndamere, Varus, Lee Sin, Penta Olaf, and Pantheon are quite sexy, and quite sexual. Their splash art highlights their masculinity and their physical prowess (bulging arms, pecs, naked in the cold, heroic stance, being a drummer, etc). And physical dominance, my dear, is sexy. To me. And muscle are unsexy. To you. I agree on your points that female champions are overwhelmingly (and quite disproportionately) oversexualized, but I think you have to turn your subjectivity down a notch when it comes to male champions and what makes or breaks sexual objectification for them.
Unfortunately, societal gender role and values come into play here and that's a very messy thing to buck against. For instance, I find Pantheon's splash art of him looking aggressive as all hell and very tense to be rather hot. But that's because society teaches us that males *should* be sexually aggressive and dominant. That's not something Riot can magic away, they just have to be more aware of how they cater to both their drawn-to-males and drawn-to-females audience.
PS: Additionally, MY list of sexy male champs:
Nasus - Great arms, great thighs, especially if you look at the Chinese splash. Then again he's a dog. So...yeah.
Garen - Good lord, this man has the jawline of a Greek god. I can't decide if I want to run away with Rugged Garen or Desert Trooper Garen.
Ryze - Shoulders! Biceps! Pecs! Abs! Are you sure this guy is a spell-flinging mage? Because damn, he is BUILT. A few points off for that god-awful beard though. Can we get a sexy Five O' Clock Shadow Ryze, or Well-Trimmed Ryze?
Malzahar - Ok, to be honest I didn't think Malzahar was hot until I saw Taco Storm.
Xin Zhao - Oh. My. God. HERE is Xin Zhao's original design. I would follow this man. To my grave. This looks like a man fierce in battle, stoic in the evening, and gentle in bed. This is the man my man could smell like. The final design? 7/10, would still do. I mean, look at the Chinese splash for the Viscero skin. Now THAT is a gladiator.
Gangplank - He's a pirate. Before his remodeling he had some serious pec cleavage and chest hair going on, and after his remodeling he found some very well-defined biceps. He can board my deck however he likes.
Jarvan IV - Look at his classic skin. Look at it! Those pecs! Those abs! That tight black spandex! Seriously, Jarvan. That **** is for ballet and modern dancers.
Udyr - Don't laugh, but I think a hippie who communes with wild animals is attractive in his own way. Granted, he probably smells funny and doesn't know what shampoo is, but when you're both at Burning Man, who's gonna care?