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.
Most is Slay the Spire, and I don’t even think it’s close. And I say that having bought it twice, once on Steam and once on mobile.
Least, I’m tempted to day League of Legends or Overwatch, both of which I bought extra cosmetic stuff for and neither of which I play anymore - and I’m not sure I even liked either of them much when I was playing.
But not knowing (and not wanting to know) how much money I’ve spent on either, I’ll instead say either Imperator: Rome or Victoria III. I preordered both with extras, and ended up only putting around 40 hours into both before giving up. Compare that to other Paradox grand strategy games, where I can easily have 500+ hours played, and I really feel like I didn’t get my money’s worth.