I have the BFGoodrich Kdw tires and they are really good. It's amazing how hard I can drive into a turn and the tires just keep gripping. They definitely get my vote.

 

Any of those 3 are good choices. I've have the KDW, some friends have the SZ50, and some have the Potenzas.

 

id definatly say the g-force kd or kdw if you only plan on using in dry weather these grip best out of the 3 you listed the 555 extreme performance are also excelent if you dont have to worry about rain or snow or weather other than sunny.

the potenza re730 are great for all weathers, although not what i would go with if im just gonna run the tires in the summer.

ive heard really good things about the Z rated falken ziex that come really cheap and handel awesome, but i cant say yes or no cause i havent experianced them only heard from customers.