I can routinely break 250k points (3rd rocket). I start at level 7, and generally hit about level 19. I probably have around 25-30 tetrises. I play the original gameboy tetris. My legs usually fall asleep and I have to get off the toilet.
My highscore was like 515,000 or so.. I can't remember exactly, just that it was a bit over 500k. I actually didn't even hit level 20 on that game, it was just one of those super lucky games where I got almost nothing but Tetrises.
I was real pleased with myself beating my mom's score since she played way more than me. Then I found high score pages with dozens and dozens of people maxing out the score at 999,999 and stopped feeling very good.