I use Uncle Bud's 15" Bull Bag. This was primarily for field use to shoot off a platform, which sits across the bed of my truck while varmit hunting. It also gives me excellent results at the bench.
I'm sure a lot of the other fancy bench type rests will provide a more stable rest, but this is an all around rest that I now use all the time.
If you want the best, I'd have to go with a Sinclair Rest and a rear bag but I don't shoot competition and can't afford the best :wink:
Good Luck Choosing,
Stan