My favorite organized rides are:
the Horrible Hundred in Clermont, FL...sorry, just last weekend (Nov). Very well organized, over 2,000 riders and the worst intersections have police letting you safely through, beautiful area and wicked steep hills, though brief. They always have the best t-shirts...colorful and cute...and it finishes with a lunch that includes salmon or some other really great fish well done as well as the usual burgers and brats.
Mt Dora Bicycle Festival, Mt Dora, FL ....Oct Pretty area with lots of lakes and hills, antique shops, beautiful terrain, and a folk music festival the same weekend in a nearby town.
Tour of Sebring Bicycle Event, starts and finishes at Kenilworth Lodge, Sebring, FL Stay in an old grand hotel from about 1915, fun events like ice cream social, DJ night, and really nice riding.