I have used:
Lone Wolf - Best Value!
KKM - Recent price drops may make them more price competitive.
Accu-Match - Don't know if these are still made, but had to quit using it in matches! My wife and I can regularly put 2 bullets through one hole... most amazing barrel of any firearm I have shot. ONLY happens with this barrel!!! If you find one (9mm G19) let me know!
The Lone Wolf and the KKM shoot very well, both cycle easily, no problems with either brand. I have 6 to 8 Lone Wolf barrels, and I'm thinking only two KKM.
Had to file the front of the barrel hood on the Accu-Match barrel... may explain the '2 bullets/one hole' phenomenon...