1978 Volvo 242GT
Price: A hair under 10 grand
Why it's underrated: I shouldn't have to explain that Volvos are historically underrated choices when it comes to classic cars. It has something to do with their reputation for placing precedence on safety and utility. If a typical Volvo of the 1970s had as much soul as a bowl of Wasa crackers, the 242GT was the turbocharged herring that put hair on the chest of newly minted Volvo converts. Yes, it's boxy to an extreme, but it's also quick, stylish, and different than other desirable imports of the time -- including the classic Volvo you're supposed to love, the P1800.
There's a quality alternative, too: If a 242GT, specifically, isn't available when you're searching, Volvo produced a lot of 200-series coupes, and they all embody the same offbeat spirit.