I've managed to get to level 19 then collided to my death. To this day, I still can't get that far. XD
Some of you may have gotten farther than me. So, how far did you go in Tetris?
EDIT: I'm referring to the NES Tetris version. (the classic) However! If you don't have that one and have played other versions, please feel free to post your answer anyway! XD