Disclaimer: it has been several years since I took them, but if you are willing to limit yourself to seafood, I highly recommend the classes at Coastal Seafoods. I've taken two classes there. The "ambience" is non-existent. The chefs have never been nominated for Beard awards. But the quality of the ingredients was beyond compare. Both of the classes I took were participation classes (though you didn't have to participate if you didn't want to) and they served way more than a dab of this dish and a dab of that. Good recipes, too, some of which I still use occasionally.
Mrs. sisp and I took a class at Kitchen Window last summer (in their old kitchen). It was a lot of fun. Again, the chefs were not "names". But their recipe for grilled crab cakes has become the standard by which we judge all other crabcakes now. And there was the bonus of trying out all kinds of equipment that they sell (Shun and Global knives, Capresso espresso machines, etc.).
And there is the grand dame, Byerly's, out in St Louis Park. I've taken classes there from the likes of Raghavan Iyer and Beth Dooley, and, at least in the past, they've featured guest chefs on the order of Scott Pampuch (don't know if he's ever done a class there, but that's the level of talent they [used to] attract).
74 Snelling Ave S, St Paul, MN 55105
3001 Hennepin Ave, Minneapolis, MN 55408
3777 Park Center Blvd A, St Louis Park, MN