No one place has the best in all the categories you ask about:
Chaa Creek has by far the nicest cabanas especially their newer garden suites. The regular cabanas are duplex units and sometimes you can hear your neighbors.
Best food? That really depends on when you're there and who's cooking. All are good most of the time, not gourmet but well-prepared and filling. But I'd probably say Ian Anderson's..
Setting? Another tough question. Chaa Creek has by far the nicest grounds (manicured, well-maintained, large staff takes there care of them), but Ian Anderson's and Pook's Hill have more of a "real jungle" setting.
--Lan Sluder
Belize First Magazine
http://www.turq.com/belizefirst/