I've had steak at Le Cellier, Shula's, California Grill, and Concourse. It was definitely good at all of those places, but if I were to rank, it would be:
1. Shula's
2. CG
3. Le Cellier
4. Concourse
The beef at Shula's was unbelievable. I wasn't going into it expecting it to be that good. I've had steak at all of the big name places in New York so I wasn't really prepared to be surprised by any of the steak at WDW. I was. Cooked to perfection. Service was impeccable. Bringing out all of the meats is a little much, but the rest of the experience was top shelf. The side dishes at Shula's are also top quality and plentiful.
California Grill was also great, service exceptional. [EDIT: I had the filet at CG, and the preparation was immaculate. The beef was extremely tender. We also had one of those flatbreads, which oddly enough was a great complement to the steak.]
Le Cellier is good, definitely better than Concourse. LC is a nice option if you're in the park and don't want to leave, but if that's not a concern, Shula's is just down the boardwalk at the Swan and is definitely worth it.