I've been re-acquiring some old gaming consoles lately and it seems official SNES controllers are getting pretty expensive these days, commanding $15-20 at the time of this writing. I already had one official controller but wanted to get a second controller on the offhand chance anyone wanted to play a 2-player game. I wasn't too keen on paying the full price for an official one, so figured I'd try out the Tomee SNES controllers, which are super-cheap and readily available (i.e., no eBay; I got a 2-pack for ~$7 on Amazon).
However, the plastic feels a bit flimsy and the d-pad is shaped a bit differently from the official Nintendo controller's (it's significantly fatter than the Nintendo version; Nintendo on top, Tomee below):
Overall, I think these controllers are a great value for someone who wants to do some casual playing or, in my case, just wants a second controller on-hand for the rare occasion that a friend/guest wants to throw down on some multiplayer action. If you're serious about your gaming, though, you'll want to have an official controller, which is more reliable, more comfortable and built to last.
If you're planning to use an SNES-to-USB adapter to use a real controller with an emulator, I suggest looking instead at the Buffalo Classic USB Gamepad, the price of which varies from around $12-20. This controller feels significantly more solid than the Tomee and actually feels extremely similar to a new official Nintendo SNES controller in weight and button-feel. Here's a (shitty) picture of mine next to one of the Tomees for comparison: