All Sega Master System and Mega Drive controllers will work on Amigas as 2-button pads (buttons B and C on the Mega Drive pad work as buttons 1 and 2).
What ever you do though, don't ever plug or unplug the controllers while the A1200 is switched on, because it can blow a CIA chip, and you'll lose your right audio channels.
Oh, and Sega phaser guns don't work on the Amiga, unfortunately.