Nitto NT555's. I have an 05 GT and live in florida as well and I love these tires. I got them about a month and a half ago and have already put on a couple thousand miles on them and have not noticed any wear. They perform great in dry conditions and have a pretty good amount of grip, and they are decent in really wet conditions. Last night I got caught in a really bad rain storm on my way home from work and I couldn't get them to break traction so to me thats pretty good.
2005 Mustang GT. K&N CAI, Pypes O/R X-Pipe, Corsa Axle-Back, SCT SF3/X3 Tuner with 93 Race Tune loaded, SR Lowering springs, BMR LCA's, 10" RE Audio SEX10D4 Subwoofer with Hifonics Brutus BRX1100.1 Mono Amp in a ported 1.10 cf^3 box.
2011 Yamaha FZ6R. Two-Brothers Black Series full exhaust, Fender eliminator, bar end mirrors, 6000k HID, Michelin Pilot Road 3 tires.