Other semi auto 5.56 rifles (not AR/AK/Mini14 style). Not a complete list, but these are most of the ones available nowadays (availability depending on your wallet). I probably missed a bunch, but this is just a quick run down of the modern/aftermarket supported/readily available models.
Robinson Arms XCR-L
IWI Galil (AK-style, but not really an AK)
LMT/LWRCI/POF/Adams Arms/PWS Piston ARs (not your father’s direct impingement)
Desert Tech MDR