Nearly anything.
Representative brands...
Effective and cheap: Derby, Shark, Zaza, Voshkod
Slightly higher but still cheap, may or may not do a better shave: Perma-Sharp, PolSilver Si, Gillette Silver Blue
Famously sharp, yet higher, but still cheap, may or may not do a better shave: Feather
Outrageously expensive for DE with no performance difference: Merkur
Consider visiting Tryablade and do some exploring.
Suggestions for Merkur blade replacements?