'Course, the big question is: What kind of sailing do you plan to do?
My brother just bought a Bayfield 25. It has a 3 foot draft. We've got it down at Breezy Point at the moment. The draft is good for most places. However, if you are looking to get into the shallower areas (like parts of Cambridge), forget it for the most part - you'll want a more shallow craft. 'Course, you'll sacrifice some stability for that, but what do you do?
I'd say between 3 and 5 feet is where you'd want to stay based upon my observations and calling around to marinas for mooring. 5 feet is going to be tough to get slips (or, rather, inexepensive slips), and 3 will be easier.
Just my ill-educated two cents.
/s/ Jon C. Munson II