In the past month I've had three controllers go bad on me.

First was a first-party NES controller. It seemed fine at first, but when I tried to play Contra two-player it refused to recognize button inputs.

One of them was a Sega Genesis SG Propad 6. I have two of these, and one of them (fortunately) still works just fine, but I had bought two for two-player games (I hate the official Sega 6-button controllers... they are way too small for my hands). The second, less-used one developed an issue where it always thinks I'm pointing down, even when I'm not.

The other controller that's gone bust on me is a PSOne Dualshock. I was playing Medal of Honor and noticed that sometimes the analog control randomly shuts off. Later, when playing Gran Turismo, I noticed that half the time the vehicles always veer to the left. Even when that doesn't happen, they seem to prefer turning left to turning right. It's forced me to play with a PS2 controller, which I think may be too sensitive for Gran Turismo (cars keep spinning).

Unfortunately everyone tells me that the first-party Playstation controllers are the best and most durable, so it looks like I have to just buy another one and hope for the best.

... Unless anyone knows how I can possibly repair these controllers to fix these issues?