I bought FFX multiple times because, for reason, the disk for that particular PS2 game kept going wrong. Other PS2 disks got damaged from time to time and needed replacing, but nothing like as often as FFX did. I also bought the remaster for both PC and console, so count those and I must have bought the game on 5 or 6 separate occasions.
Then there some of the usual suspects that launched again and again on new hardware with new updates like Skyrim, but I think my buy count for that sits at 4, which isn't bad.