For our family it's the Yachtsman at Yacht & Beach Club. We have been going there since our kids were 4 & 5 (that's 14 years) and we wouldn't consider a visit complete without dinner at the Yachtsman. We have never had bad service or a bad meal there (this differs somewhat from what I have read from others). We love it!
I, too, have to say that the Yachtsman Steakhouse has the best steak. Of course, it also depends on what kind of steak. I think the best filet mignon is at V&A's.
My favorite is the filet at Jiko. Yachtsman has a number of great steaks and CG and FF (of all places) both also has great filets. Never been to Shula's at WDW, but the one near me at home is wonderful.
As for LeCellier, I have enjoyed meals there, but never had anything there that I would put up against the steaks at the places mentioned above.