Madhouse, no doubts. Now, (hopefully, lel) hope for second seasons on their anime has finally appeared! MAL just put One Punch Man 2 in their database and I'm now awaiting any potential article(s) about an official announcement so that I can be officially hyped (not exactly for OPM, though).
You have enemies? Good, that means you stood up for something.
Bones is always a safe choice, and MadHouse has made some amazing things.
But I think I'm going to have to go with David Productions, so far the only remotely popular thing they've done is JoJo's, but they did SUCH an amazing job of it, better than anybody could have asked, and for a studio that nobody had ever heard of that's impressive.