My DS6 really enjoyed the Sandcastle club. We hadn't really planned on having him go there but early on in our trip we stopped by to take a look inside and DS asked if he could go one night.
They have video games (PS2, X box and full-sized arcade games) a dress-up room where kids can dress up in costumes, coloring stations, art classes, board games, pretend games, etc.
I think the cost was $11 an hour and they serve dinner. I think he stayed about 2.5 hours and wanted to stay longer when we came back to get him.
I wish they would have taken DS1 as well!