Sheraton Safari doesn't have a zero entry pool, but does have a slide. Cypress Pointe doesn't have zero entry pools, but does have slides, but not great slides in my opinion. More like playground slides. Sheraton Vistana Resort has a zero entry pool, but no slide at that particular pool. There is another pool with a slide. Out of those three places, I think Sheraton Safari has the best slide.
Those are the only resorts I've been to close to DTD, but I'm sure other people will have plenty of suggestions.