The renaissance is actually the closest hotel, and it is awesome!
Its an easy walk across the street, but they have a shuttle.
We stayed at the Hilton Garden inn
http://hiltongardeninn3.hilton.com/...en-inn-orlando-at-seaworld-ORLSEGI/index.html
I loved it. We just took the walking trail to seaworld and had no problem.
It was also our 10 year wedding anniversary and they treated us so GREAT !!! I would stay at that hotel again.