Meryl Silverburgh, anyone? She's pretty badass and sassy without being Bayonetta sexual or completely asexual, I think.
Also I've never really taken offence to anything like that, and while I'm sure some people would say that makes me a terrible woman, I think some ladies just need to chill out. Yes, Bayonetta is outrageously sexual, but at least she isn't cracking out daddy issues or fucking everything in sight. Alyx might not be feminine enough for some people, but think about it - if a young girl in the company of an older guy - her fathers friend - on a series of missions that put them both in danger, but through which she can completely hold her own and is totally competent and independent, suddenly got her boobies out or whacked on skirt, or started flirting, or being girly, I'm sure they would have something to say about that too.
"Ooh, why do young girls have to be objectified this way," they would say. "Even Gordon Freeman is a perv!"