I always take the Free rooms on my Comp, why pay Anything if you don't have to?
Bally's from the Pics I've seen appear to be the best but I've never stayed there preferring the Location of the Flamingo even over Harrah's. Sure the Std Flamingo rooms are a little dated but so is my whole House! What do you Expect? The rooms in Harrah's seemed Cramped to me especially with their small windows. The Flamingo Std rooms are good enough for me, with the floor to ceiling windows they at least felt bigger. I even lucked out on a top floor strip view the same week last Dec.
I've got 2 nites Free in a couple weeks but my Gambling Buddy has the whole 5 nites Free so it's the Flamingo again for the 3rd time. Location, Location, Location!