There's also a Comfort Suites close to the port. It's actually called Comfort Suites at the Port. All the rooms are suites (obviously). They have free shuttle transportation to and from the port. Also if you drive down there you can park your car there for $12/day as apposed to the $20/day it costs at the actual Port of Miami.
We're staying there just for the cheap(er) parking and free transport.