Several people never returned my games after I lent them to them, so yes.

Stolen? No. Not returned? Yep. That's the last I saw of my Warcraft 3 and Frozen Throne... It's all forgiven though.

Yeah. My Need For Speed II SE..brought it to my cousin place for the holiday, when its time to go back, the game is mysteriously missing and nobody seems to know. I rmmber perfectly it is on top of his computer desk.
Didn't confront him, i just let it go after a while. But still...

Nope, I've never had a game stolen (that I can remember). I've had books borrowed and never returned? O_o

That's perhaps even worse because books, unlike CDs become better with age! I've been trying to get my copy of Do Androids Dream of Electric Sheep back from a very good, but incredibly forgetful friend for years now. I probably won't ever get it back though, seeing as he's moving to Australia later this month :P

Nope.

I weeded out my PS1 game collection once and wanted to sell some games on the flea market. I had my back turned for about 2 minutes to set up a table and when I turned back they were gone. It could've been worse considering they were games I didn't want anymore anyhows, but I would still have preferred to get some money for them.

Unfortunately, I am one of those friends that borrowed a game and never gave it back. I borrowed Unreal Tournament from a class mate some 13-14 years ago and still have the disc though I lost contact with him after I finished high school.

Never a game but in high school some asshole swiped my Ministry Psalm 69 disc.

A former buddy of mine borrowed my original boxed copy of Sacrifice, then moved to the US without returning it.

Does CUT and PASTE counted as stolen?

Also few old Ninja Turtles cartridge and original DVD of Dark Star One and Journey to The Center of the Earth went missing while I was away for my college. I never got a chance to play them.
So was my LinuxGamers live DVD and a disc full of OpenSource games.

Not Licurg?

Hehe, no, not Licurg ;-)

NES cartridges? I would've been fuming! If we're talking about tmnt 2 or 3 that is. Not so much if it was tmnt1. I might even have been glad had somebody taken it :P