My favorite is the InterContinental, though it can be pricey.. but occassionally I've got a great deal on it with Priceline.
Hyatt is nice, and only a couple blocks further away.
Marriott Biscayne Bay is great too.. but also can be costly.
Holiday Inn is great because it's directly across the street from Bayside Market Place, but I didn't like the hotel. And wouldnt stay if it was for more than one night.