To date, if you like roundwounds, the Fodera nickels are really good, way far better than the D’Addario nickels which is a standard to compare other brands. If you want to go to tapewounds, I've tried (almost, as you can't be sure) everything available on the market and the best tone will be achieved with the LaBella gold white nylon, but I love very fast attack and endless sustain on fretless... And I hate flatwounds on fretless, because they kill the sound I want to hear.