By far the most popular and durable in my area is the HiTec 5955TG & the 5995TG . I've been running the 5995TG very hard in my buggy for a year now with ZERO Issues....
They have Ultra strong Titanium gears, 333.29oz, 0.12 Sec & Ditgital. Shop around and you can pick them up for $89.99 each.
http://66.221.209.115/html/hsr-5995tg_ultra_torque.html