Always a fan of coffee shops, largely because I enjoy tooling around with books, and chasing the opposite sex isn't really the point of the activity. Also, coffee shops in/near bookstores provide free context to strike up a conversation. Bars tend to put a bit of pressure into things, so most people I run into tend to force conversations along (rather awkward), or become shy, and just stand around (equally bad, but easier to overcome).
Really, though, be open to meet people (and not for dating alone) pretty much anywhere. I've met some interesting characters on the NY subway, airline flights, in lines for concerts, while repairing a fan for Habitat for Humanity's re-use center, and a bevy of other places that I wasn't really looking for.
I'd suggest not really going "date-hunting". Simply roaming around, looking to meet interesting people is far more fun, and tends to lead to some entertaining stories, as well. And if something more comes of a random encounter, so be it.