Dont really have one big win, but probably got to ~5BTC just from 0.2 or so over the month with sports betting.
Granted, the big amount of luck was needed because i was going all-in at first to build somewhat of a roll, and after ~1 BTC switched to the more standard bankroll managament and grinded it from there.
It was a long time ago though.
I never gambled more than small amounts and now I stopped gambling entirely except some betting and poker but I enjoy reading the occasional story about gamblers and big wins.
For example, the story of the two friends who sold their travel website then bought a Las Vegas casino is great