Uhhhh I guess a large percentage of NPCs would be "not sexy" I think. Pretty much all of Fallout: NV, 'cept Veronica and Cass and the few hilarious "advertisers" outside a casino.
Persona 4 had that one fat girl who was pretty comedic and/or tragic. Hanako was it? Her and the one teacher who was trying too hard.
Pretty sure your thread should be re-titled because there have been so, so many of them. You just don't notice because they're unremarkable, part of the background. You know what draws attention? *Explosions and hot women. Nothing more, nothing less.
Really attractive characters are just easier targets these days so... I could think up and write a really intelligent analysis here but it's 10:30pm and I have no fucking idea.
[sub]*Disclaimer: This was a joke. Don't start anything on me over that dammit. Darn people and their lack of humour sensors[/sub]