The best and most messed up for me was I was working/living third shift and I had a morning class but had been playing Lumines Plus on PS2 all night. I went to class the next morning and I kept seeing Lumines blocks forming around my professors afro. It was honestly pretty cool. Nothing like drug free hallucinations.
not tetris or anything but resident evil 4, i kept feelin like everyone around me was a ganado when i was walkin in my schools hallway. and my brother almost accidentaly ran over people when he picked me up from school cause he thought he was playin grand theft auto
DmC's story mode in 8 seconds: http://www.youtube.com/watch?v=flH8MZo-4jw
I remember a particular summer where all a friend and I would do is play tony hawk 2, eventually to the point where every time I saw an edge I would look at it as something to be grinded. Also, I've specifically suffered from a literal tetris effect in that I played so much tetris that I began to see falling blocks when I closed my eyes, and had nightmares that lines of tetrominos would stack up in the playing field perfectly but never clear.
"Believe none of what you hear, and only half of what you see."- Alfred Glaser