What's a good restaurant in Chicago?

I’m trying to buy a restaurant gift cert as a wedding gift for some friends who live in Chicago. Don’t know the city myself. I’m looking for something mid-top end (ya know, $18–25 entree type place). Something that young people would like (not too stuffy, maybe even ‘hip’). Maybe something local-organic style? Any recs? Also would be interested in getting them a cooking class if there’s anywhere worth looking at for that…