Oh boy, OK. Don't judge me.
Batman: Arkham Asylum/City/Origin/Knight, Mad Max, Divinity Original Sin, Oblivion, Skyim, Fallout 3 and 4, Fallout New Vegas,The Witcher 2 and 3, Darksiders 1 and 2, Banner Saga 1 and 2, Elite Dangerous, Bioshock 1, 2 and Infinite, Borderlands 1, 2 and Pre-sequel...
I'll stop there, though the list goes on. Almost every game I own, I own on PC and one, maybe two consoles. I have a problem...I know this.
There are a few that stand out. I pre-ordered two copies of Mass Effect 3, the collectors and the standard on Xbox 360, then later bought it again on PC...and PS3, I regret nothing. I bought the collectors edition of Arkham Asylum on PS3, didn't like that it came in a sleeve instead of a plastic case so I traded it in at Gamestop and bought the standard edition. THEN I traded that in, only to later buy it on Xbox 360, and again on the PC. Lastly, I bought Gears of War and Resistance, traded them in, bought them again, traded them in, and bought them yet again...only to trade them in and later buy them once more. I think they were under a dollar the last time I bought them.