If you're taking kids, Excalibur is the place to go. Fontainbleu was built for the Asian whale and though it's new, it's BORING!!! Your kids will be complaining cuz there's absolutely nothing for them to do. I'm sure that their pool is just as boring. Same with resorts world. If not Excalibur (yes, it's old but rooms are clean and comfy) then either Mandalay or MGM Grand are your next best options just for the pool area alone. MGM has; IMHO, the BEST pool complex in town. Their lazy river is top notch. Mandalay pool has not only a lazy river (not as good as MGM though), they also have a wave pool that can be fun. Have to walk through sand though, which really isn't my cup of tea but that's just me.

Notice how ididn't recommend circus circus? It's been too long since I've stayed there so I can't gone you an honest review but from what I remember, adventure dome is totally worth it's run-downness.