That depends on your definition of switchable.
If you mean physically restricted, to prevent travel into the diagonals, then the Prodigy, Magstik, and T-stik are the only ones I can think of.
If you mean a stick that will switch functionally, rather than physically, the list grows considerably.
In addition to the Suzo (which is still a manual changeover), you can get any 49-way (Williams, Midway, Happs), and use the GroovyGameGear 49-way interface, or you can get the U-360 from Ultimarc.
Both of these will switch automatically, as the individual game loads, and always be configured properly for the game that is playing.
That is a big plus to me because you don't want your guest trying to play an 8-way game with a 4-way, or vice versa.