I have been using the hi-torque servo w/metal gears from Futaba for about 9 months. It has worked well for me and is fairly affordable. If you are looking for durability then metal gears are the way to go. I'll let the TeamSC10.com readers post their recommendations as well.

Buy the Futaba S3305 High-Torque Servo w/metal gear

Post below if you have a servo you want to recommend to other SC10 owners.