Occasionally I open up and clean my controllers, maybe use a little oil on moving parts, other maintenance like that, but if the rubber domes under the buttons tear, I have no way to repair it myself.

I've tried buying rubber dome replacements for SNES, NES and GameBoy from various sources, some who charge a lot more, some who charge a lot less, but I find the quality is generally terrible, and ones I have paid more for were indistinguishable from the cheapest ones. In particular d-pad rubber domes can make a big difference regarding precise diagonals, or accidentally pushing diagonals.

What I've ended up doing is buying 10 or so cheap ones from eBay, and then one by one put them in the controller, screw it back together, test it out, repeat. The quality may be poor, but it's also inconsistent, and what I find is that out of 10 maybe 1 or 2 feels okay for the d-pad.

Push buttons seem to be less demanding, I guess because they're more constrained in their travel. Generally I find most replacements are okay for those.

Does anyone have a good experience trying to find replacement rubber domes? Does anyone make some that are consistently good? Or maybe is there a good way to repair old ones?