I have worked frequently with an agency in the UK called ‘[URL=“http://www.ugly.org/”]Ugly’ (hiring models and actors, not as one myself, I might add).
Some of the people on their books are quirky/weird/ugly, most just look like ordinary people, which is often what you need if you’re doing an ad campaign that needs to feel real.
Have a look at the ‘specials’ section.
I don’t know whether they’re currently available in the US, but a few months back I watched a series of documentaries on that agency, Ugly, from YouTube; I did find them quite interesting. As SanVito says, some are extremes (“the most pierced dude in the UK”), some are on the outside of the curve (“BBB waitress/dancers”), some were… the woman in soap adverts.
I recognise a few of the “wee folk” from that agency. Many of those are regular actors on British TV (the dwarf Bolton Wonderers supporters who attack Max in Phoenix Nights, for instance).
He’s a special case, though. It’s not just that he looks like a half-crazy hardass Mexican ex-con. He is a half-crazy hardass Californian ex-con. Or rather, he was up until the day he got his first Hollywood gig through a scriptwriter he’d met behind the bars of San Quentin :).