The ones I'm most guilty of are
RE4 - GC, PS2, Wii, PS3, PC.
I drew the line at the PS4 version, lol. To be fair, each version had a new feature, PS2 had new Ada missions, Wii had motion controls, PS3 was HD, PC was HD textured and 60fps.
God of War series: PS2, PS3 HD collection, PS Vita, PS4 (only GOW3 Remaster)
Mass Effect series: 360, PS3, PC
FFX: PS2, PS3, PSVita (almost bought it on PS4, but missed my chance for it at 8$)
Others games I've only bought twice are:
The Last of Us: PS3, PS4 remaster
Uncharted series: PS3, PS4 remaster
Kingdom Hearts series: PS2, PS3 remaster. (thinking of getting PS4 remaster, but I dunno yet.)