The Grove has some great ones, particularly their Farmer's Salad. The Insalata Il Vicino at Il Vicino is very tasty, and I am also a big fan of the chicken salad at Farina. I haven't been to Relish since they closed their downtown location, but I used to really enjoy their "Chop Chop" salad.
The Standard Diner used to have this great spinach salad with beats, grilled pears and brie. Looks like they may have dropped it from the menu, but I'm sure some of their other salads are equally as delicious.