For a while now I have been using BrassCraft quarter turn stop valves (model #29). These are not actual ball valves, they are the valves with the cylindrical grey plastic rotor which rotates inside the chrome plated valve. I have used about 50 or so of these and the problem with about 10 of them is that they do not seal internally after a while. To be clear, they DO NOT leak externally, as in they do not drip inside the cabinets. What they do is bypass INTERNALLY past the grey rotor and allow the faucets to drip when the valve is closed. I think that just a little buildup scratches the plastic when the valve is turned. So, they flow water, they don't drip into the cabinets, so that is good, it's just that you can't completely shut the water off when you need to. So the question is: what is the best valve to use? I am not stuck on quarter turns or any particular type. I would just like a good valve that works and lasts a while. Any types or brands I should consider? Thanks a lot.