Not a game, but the Apple IIgs and games we had got sold off in a garage sale in 1992. We got an SNES and games out of it, but I really missed not having that computer. I remember wondering why the hell this nice color computer with games was replaced with this dinky little B/W Macintosh SE/30 that had jack-shit for software and a tiny screen.

Nowadays I think I just regret having sold some stuff off 10 or more years ago, instead of holding onto it longer so I could sell it for a lot more now, like my Genesis/CD/32X collection. I had some pretty rare games and everything was complete in box and in excellent condition.
But back in 1998, I sold my Playstation and games off to pay off a debt -which I owed to the game shop I worked at and had bought most of that stuff from- and really regretted it afterwards. At the time I wasn't playing it much and was mainly playing Neo-Geo and Saturn games. I figured it would be a good time to move on with the Dreamcast coming. That was a mistake. I think I lasted maybe a month with the Playstation, before buying it back after Street Fighter Zero 3 got announced as a PS1 timed exclusive for like six months.

It took me
10 years to get my collection back again. A lot of stuff I ended up buying back from the store. Then on my first trip to Japan in 2001, I went nuts in Akihabara and bought 50+ games.
I had pretty much everything I wanted back again by the mid-2000s, but one game in particular eluded me-
Toukidenshou Angel Eyes by Tecmo, which was a 2D fighting game and a precursor of sorts to Dead Or Alive (in that it had females with ridiculously-bouncy chests), that had the odd choice of using both sprite-based and pre-rendered characters. This wasn't a game that sold off to my debt, but rather I decided I was done with it and sold it to a friend before that happened. When I decided to get it back, he didn't want to sell it and I could not find it anywhere online. Both times I went to Japan in 2001 and 2004, the game went unseen. When I moved there in 2005, I did not find a copy until one my last trips to Tokyo before moving back to the States. I didn't have some burning desire to play the game or anything; I just wanted to get it back to "complete" my PS1 collection. Was pretty happy when I got a copy for 5000 yen or so.
My parents sold my NES when we moved because I had a SNES. (Image removed from quote.)
This too. My brother and father decided that the NES and games we had could be sold off without me. They got a ridiculously-low amount for everything (like a hundred-something bucks back in '93, from some mail order place in the back a gaming magazine) and the cash was used to buy Street Fighter II Turbo on SNES. I was happy about that, but not happy about losing the 50-something NES games we had.
