All of them are exceptional calibers...

the .30-06 is the most flexable of them and generally the most powerful...(thinking pig)

the .270 has the best long range ballistics...

the .308 can be used in some short action rifles (I like the Ruger M77II Compact) and is generally the most accurate round, but does not handle heavy bullets (180-220 grain) as well as the -06.

Since most stores will carry those bullets (and .30-30) when they carry nothing else, you still have a winner with each...

Since a deer hit by any of them will die quickly (and in my experience, nearly identically), you may wish to think about any hunting you may do outside of Florida...and choose based on that...