Simple question. If so, what was the dollar amount? 

A friend once borrowed Croc: Legend of the Gobbos and moved away before giving me my game back.

I've learned to never trust anyone. The betrayal still hurts to this day, what, 20 years later? Fuck Jason.

Yes, about 10 of my SNES-games were stolen, not sure how much they were worth but i assume more than$1000.

I'm guessing you owned Earthbound and Ninja Gaiden Trilogy as part of those ten games? Or you had SNES games that were CIB/Mint? Or just other insanely rare SNES games? Because I know, even the really good SNES games like Super Metroid go for about $50.

Twice...kind of....

In high school I had a friend with sticky fingers. I caught him stealing my copy of Jet Force Gemini when I saw it in his room (and my OCD allowed me to notice a few distinct marks on the front sticker). I took it back but realized days later he actually took like 5 other N64 games including Turok 2 Seeds of Evil. At that point, he had already moved everything to his sister's house. I found them years later during the PS2 era so I can confirm he took them.

The second time was when I lost almost all if my games drom before PS3 during a bad break up from a toxic relationship. When I high tailed it out of there, I only took my PS3 and games. I was unable to get my N64, SNES, PS1, and PS2 back fromher however because she "moved" soon after I did and claimed they were still packed away. Said I would get them back...never did. I think that hurt worse than the break up TBH lol.

Out of curiosity,  are you still friend with Jason to this day?

OP,

My sister gave 3 "The Sims" games to a friend of hers, and she never gave them back.  I forgot about them until now.  The total cost of those games must've been $80.

Yeah... my brother let HIS friend borrow MY game gear and all my games and then the douche moved away like a week later. He had evidently gone around the neighborhood borrowing lots of stuff from people because he knew he was moving...😡🤬

Nobody ever stole ANYTHING from me.

Some friends borrowed a few DVDs or games or other things longer than expected, but a few friendly reminders (f.e. horseheads in their beds) solved these minor problems.

Yeah I did. Like many of those here,I made the mistake of trusting too much and let a """"friend""" borrow my Tekken 3, Street Fighter Alpha 3 and Digimon World for PS1. The only time he spoke to me again he tried to convince me he had gave me back the games (he did not). Bastard...

yep I used to have two "friends" who were secretly stealing my original Xbox games. About 20 - 25 in total, so well over USD500.
EDIT: oh also they stole a PS1 copy of FFVII, which I borrowed from someone else. Guess who was the bad guy when I told him that I didn't have it anymore. Me of course...