Itaru "Daru" Hashida from Steins;Gate is one of the more prominent ones.
Daru's Steins;Gate wiki page.
He is a slightly larger man (ok, fat), and his image fits into the otaku stereotype. But what makes him different is his attitude, personality and intelligence. He is really rational and stuff.
Anyway, my favourite is definitely Sato from NHK,like you OP. One of the few anime characters that I can truly relate and connect to.