Been to Tizi Melloul a couple times and never had a complaint. In fact, the food has really been quite good. Just stay away form the Lebanese wine. (I should have known...)
I've been to a good party on the second floor of Mirai if you like sushi.
Carnivale is always fun for a crowd. Its a huge place, but there are some nice side rooms if you want a more intimate party.
I've had a couple of classes at the Chopping Block at Merchandise Mart. If you have a big enough crowd (5-10?) they will do a custom session for you - either a demo or hands on of whatever cuisine/specialty you want. Used to be BYO, but they are serving wine now too. If you're really interested, call them and see what they can do.
I've actually been to 3 different 30th birthday parties at Tizi Melloul. They have been really fun....up to 24 people I believe can fit in the crescent room which is where 2 of the parties were located. It's a big circular room with pillows on the floor, bright colors, where you dine on a middle eastern feast. They bring in a belly dancer too.
It's fun, the food is good...kebabs, kefta, hummos and the like. Drinks are good too. The room is really the experience though, very cozy and unique.
Great 30th B-day bashes:
- Tapas Barcelona (Evanston) - tapas is great for big groups of people and Tapas Barcelona is my favorite tapas restaurant in the area.
- Mirai Sushi (on Division in Wicker Park/Bucktown) - much fancier and expensive, but we all had a great time.
- Darkroom (on W. Chicago) - more of a club than a restaurant, but we all had a great time.
- Kit Kat Club (Lakeview)- good drinks, good food, good drag queens. This was for the 30th b-day party of a married female friend. I think everyone had fun except her husband.
- Thai Pastry - this was impromptu. My friend reluctantly told us that it was her 30th birthday when we were already at dinner and we turned a normal dinner into an amazing feast. Then went to Chicago Karaoke at Lawrence and Western to continue the evening in a private Karaoke room.
Bad 30th B-day bashes
- Lou Malnati's - felt like a 5th grade birthday party, but with beer.
- Spiaggia - I love the restaurant, but it was too stuffy for the crowd I was with and the atmosphere we were looking for. If you are looking for a more formal, intimate gathering, it is wonderful.