I have one of the original Olfa turntables. I've had it for at least 15 years. They still carry it here:
http://www.quilthouse.net/shop/produ...house-spinner/
It is a heavy, sturdy turntable with ball bearings. Not cheap, plus you need to buy the mat, but it is much sturdier and easier to turn than the current olfa/fiskars versions. If the mat ever wears out, you just replace it.