I use the Vater SlickNuts. I did have to cut down the combo plastic cupwasher's tube on some of my stands as the Slicknuts need free thread area for it's whole hole, not just the clamping area.
Recently got some of the new GROMBALs. Look like a great alternative, BUT:
These are large rubber grommets that mount in the cymbal hole to prevent keyholing. Their hole is small enought to grip the stand threads fairly well. Does away with the felts, too, less loose parts. However, they do not fit over the large center post in my cymbal case ;>( Probably be fine with a bag.