Best stuff, IMO, is Seoul Garden on the Rock Road near Northwest Plaza. Very long menu, very Korean clientele. (Disclaimer -- I haven't been for over a year.)
Best hidden treasure: The U-City Grill, behind Cicero's on Kingsland just off of Delmar. It masquerades as a greasy spoon, but the Korean owners make bibimbop and several other griddle-top specialties for about five bucks at lunch.
Others: Choi's introduced Korean to St. Louis when it was down on Meramec off of Grand, but its current location on Dorsett is run by Filipinos and the Korean stuff -- they also serve Filipino and Japanese -- seems like more of an afterthought. Korea Garden/Han Gook Kwan at Olive and Fee Fee is pretty close to where I live, but we haven't gone back there after the hostess/waitress *told* us what we would like and basically refused to serve us anything but kunmandoo and bulgoki. The deceptively named Peking Garden across Olive from Plaza Motors is actually all-Korean, and I've had some interesting grilled fish there and a smattering of other good selections, but it's really inconsistent, largely dependent upon how busy they are (actually, the busier, the better).
I think that's the full range of Korean in St. Louis.
re: Joe Bonwich
Thanks. I think I'll give Seoul Garden a try. I used to love going to Choi's when it was down on Meramec. By the way, take a look at the current issue of Saveur magazine for a good look at Korean food. It says, among other things, that there are 450 Korean restaurants in Los Angeles! Seems as if we could have more than 3 or 4 in St. Louis.
re: Alan Freed
Ended up going to Seoul Garden on Saturday night, and I was not disappointed. They don't have the long menu Joe mentioned, but, as I am relatively clueless about the cuisine, the waitress made excellent suggestions, and a good time was had by all.
I was surprised at how empty it was. Please go so they'll stay in business.