(1) Golden Nugget - My favorite is now the Golden Nugget, I think...especially since they have redone it...can't wait for the pool area to be done though. Have played there before, but last weekend was the first time I have actually STAYED there.
(2) Tropicana - I get discount (and now getting free with slot tourney entries) at the Trop. I am most familiar with it, we go to Vegas probably at least 3-4 times a year, and are there for the NFR and PBR finals each year, and have pretty much always stayed at the trop. It's "quaint" and pretty small...need some upgrades though. I like it because it is one of the remaining "old school" ones.
(3) Wynn - I really like the casino at the Wynn...it is HUGE and very nice...have not stayed there in a room though, so can't help with that.
(4) Sam's Town - stayed there during the PBR last year...lots to do there, but again, the casino is kinda small, and it is really out by itself, so there's not much you can walk to around it. I like the Sheplers being right there too...but that's the cowboy in me, I suppose. I just like the atmosphere there.
(5) Excalibur - only stayed there once but the rooms were nice - we had a hot tub in ours...it was when we were wild and just dating *LOL* So of course my objectivity might be tainted by that. We still go there for the breakfast buffet nearly every trip though.
(6) I like the MGM also...lots to see and do there, and the casino is nice and huge. Also like the rain forest restaurant there.
(7) The Mirage was nice, but again, only stayed there once. Also good food there, but wasn't overly impressed with the rooms...got the same size and as nice a room at the Excalibur for much less.

Mind you, we typically go to the cheaper casino/hotels when we go. We like a livable place, but prefer to keep as much cash as we can in our pockets for gambling rather than for the room.