Thanks for the suggestions, everyone. Please keep them coming.
Riddlemay, yeah, I ruled out Morton's on the grounds my visitors can go to the one in Boston. Thanks for mentioning Don Juan. It struck me as a brilliant idea.
Unfortunately, I've gotten e-mail from my friends being dubious about Mexican. I have written back to clarify that Chicago-style Mexican is different from what they're probably thinking of, and to ask whether that means they don't like spicy food -- in which case Korean probably isn't the best option either.
Tony, have you tried New Seoul? They use oak charcoal and we liked their spicy pork and stuffed peppers, but rice and soup aren't included (unless they just forgot to bring them -- their service left a bit to be desired). The banchan were decent, though not particularly notable, and all vegetarian.
There are a ton of Korean places in the Mount Prospect/Des Plaines area, and I've tried only a fraction of them. It might be a worthwhile project, but I doubt there are enough NW suburbanites here to make a dent.
I agree with you on Sankyu vs. Kurumaya. The latter is also probably a little more accessible to people with no Japanese.
D&J, up in Lake Zurich, is regrettably too far away. Btw, Retro Bistro was started by the D&J people, but it's now owned by the daughter and son-in-law of one of the D&J owners and managed separately.
If it does turn out the Bostonians don't like spicy food, I suspect we're back to either Retro Bistro or David's. It's been a while since I've been to either. Anyone have any fresh insights?
(Y'know, I really wonder whether people who aren't so obsessed with food worry so much about where they take their out-of-town friends ... like it somehow reflects badly on me if I pick a restaurant they aren't absolutely thrilled with.)
New Seoul Restaurant
847/439-3720
638 W. Algonquin Road #4
Des Plaines