Bootlegs notwithstanding, there's 3 main options for a SNES flash cart: Super EverDrive X5, Super EverDrive X6, and the FXPAK Pro. The FXPAK Pro is the best one, but it costs over $200. The Super EverDrive X5 is on krikzz's website for $59 and the X6 for $99. You can find a compatibility list (or rather, an incompatibility list; very few games aren't supported even on the X5) for each cart online. Same for lists of which carts have which features.