Including DLC, micro transaction purchases, etc. If you got a game for free, please also list your non-infinite next best.
For me it’s Team Fortress 2. $100 total spent on hats and the Orange Box back in the day, 4200 hours plus of fun, meaning 2.3¢ AUD per hour. Initially I thought DotA2 would be my best but it turns out I’ve spent a lot more money in that game than I thought…
My worst is God of War: Ragnarok. Bought it full price for $95 AUD, only played 2 hours and hated it, meaning $47.50 AUD per hour.
Probably either:
Warframe - played for free for 500 hours, felt guilty and bought a $20 plat pack to thank them for all of the good times before quitting the game.
Monster Hunter Generations Ultimate - bought for $10 on the eshop, 1000 hours later still going strong.
Not sure about what’s least. Technically any game I’ve bought that I haven’t played yet, I suppose, but the game I felt worst about buying was Quest for Camelot for Game Boy Color when I was a kid. I went to the store with my parents to spend my birthday money on a game for the new Game Boy Color I’d just gotten, but they didn’t have any good GBC games. I knew that I should just wait, but I really wanted to buy a game. So, I caved and bought it even though I hadn’t even seen the movie, and it was predictably terrible, and I’ve never forgotten it.
I’ve regretted that purchase for almost 30 years now.