Yeah, I don't really know how 'romantic comedy' is defined, either.
If it's a comedy based solely around boring-ass romance, sure it's going to be boring- but what about comedies which happen to have romance in them, amongst other things? Safety Not Guaranteed (which I recommended earlier and you totally need to watch) is a good example.
Alright, I can work with that definition.
Let's see:
Chungking Express - One of the more cheerful(the most cheerful?) of Wong Kar-Wai's movies. There's actually two practically separate stories in there, about some random people's romantic affairs in one of Hong-Kong's huge apartment blocks. It's very kinetic, doesn't whitewash over the cramped, often dreary setting, nor over human foibles and quirks. It's somehow super cute without being even a tiny bit saccharine. It'll leave you feeling good.
Girl on the Bridge - About a suicidal nymphomaniac and a down-on-the-luck knifethrower. It's French, it's black and white, it's both artsy and shallow, probably intentionally. It doesn't take itself seriously, and it makes you empathise with the fucked up characters. It's not great, but it's different enough to make you feel like it's more than the sum of its parts(one of which is Vanessa Paradis' arse, if you're into that).
In July - A guy chases a woman to another country, with the help of another woman, for which he inevitably falls in the process. Predictable plot? Yes. What's fun about it is the execution, which - this being a road trip movie - takes the characters from Germany through some dodgy Balkan countryside and nightlife to Turkey. Often feels like one of Kusturica's films, if you've ever seen one.
Huh, it's surprisingly hard to remember any great ones. Even of those three, only the first one is really great, the other two being just good.
You know what's fun? Weird films. Like "A Field in England". It's about an alchemist, his master, a bunch of 17-century soldiers, magic, magic mushrooms, and the power of friendship. It all happens on a field. In England.
It's sooo weird.