Milhouse is one of those characters who could have easily become a caricature of what he was in the earlier seasons, Flanderized to be just a geeky friend of Bart with just about every facet of a social pariah. Thankfully, however, he's managed to be pretty well-rounded throughout the run (the same can't be said of other supporting characters). That's not to say he doesn't consistently become the butt of jokes thanks to his uncool nature - in Regarding Margie he proves plot essential when he cockily reveals he's now lactose tolerant. Brilliantly, this isn't just another ailment thrown in by the writers to go along with his poor eyesight and asthma - the fact that Milhouse was lactose intolerant was set-up in flashbacks in Lisa's Sax. Yes for continuity.
