I'll second the Hol. Inn with an asterisk.
Read the article here about Price line. We ended up getting in the Intercontinental for $10 more. Mega sweet.
The little park along the water between the Intercontinental and the Market Place attracts homeless people and beggers at night so be forwarned. Ive never had a problem the six times Ive stayed in the area but some people arent used to that stuff. Miami PD usually has a pretty heavy presence at the Market Place.