There are providers that focus more on volatility but I think you can find some very hard hitting games from each one. Here is a little list
Nolimit: Folsom prison, Mental, San quentin
Hacksaw: Gladiator legends, Wanted
Yggdrasil, Zeppelin, multifly, vampires riches
Pragmatic: Zeus vs hades, Gates of olympus, barn festival
Netent: Dead or alive 1 and 2
Relax gaming: Beast mode
Push gaming: Razor returns
Just some you can maybe give a try.