Least enjoyment per dollar had to be Fallout 4. I bought it full price on release, roughly $60, and got the PC version, because I didn't have a working console at the time. I can only game on PC with EDSF, not WASD. But that game hardcoded Use/Action to E while also allowing E to be mapped to move forward. So everywhere I ran, if there was an action to do it would automatically do it. I kept opening doors to hiding monsters, opening crates, doing whatever when I just trying to walk around. I probably only played that game for 10ish hours before giving up.

Most enjoyment per dollar has to be NES Tetris. I have no idea how much my parents paid for that back in 1989, but I still plug in my NES and play it occasionally. Even accounting for buying a second NES in college, multiple replacement controllers, a replacement cart reader tray, and a used copy of the game off ebay far later, I am probably only in for $200. And I can't even make a guess at how many hours I've played NES Tetris. I would skip full days of school in 8th grade to play. I would play for hours in college. I still play a few hours per year now.

Most number of hours is WoW, but at $15/mo plus $60/expansion times probably 6 expansions I've probably spent over $1000 on it for a rough estimate of 7200 hours played.