Well I'm not much of a speed freak as far as my servos go. I think the fastest one I own is a .08 second response. I mostly aim for a good amount of torque and metal gears. And currently my favorite all-around servos are the xpert 4000 and 3000 series. It's got a great blend of torque and speed and can be used in any rc application. Plus the price on them is pretty hard to beat without going for an off brand servo.

But if you really want high end stuff then Highest servos are great. And you can't go wrong with the premium Hitec and Futaba servos.