The ones that are actually good at it. I loved Oney, Ego, Pebbles, Hotdiggitydemon and all on their time, but I don't believe they have maintained the quality to put out anything actually good.
The rest of good old ones are now trapped into forever ironic homo-erotic animations that are boring.
Adam Philips - Chluaid
A Brackenwood series would be great, but the short and the game will also do, please may this time work.
Has worked for Disney and in several other shows like Bob's Burguers.
Felix Colgrave - MasterAardvark
Incredibly talented australian animator boy, very young but everything he does is great. Has worked on a few shows like Trip Tank and his latest short Double King is perfect.
Alek Wasilewski - Sarkasm
Hasn't actually done a lot, first work I've seen was "Smile!" from 2004, but his short movie Lucky Day Forever is to this day one of the best animations ever featured on Newgrounds.
David Firth - Doki
Very good at what he does, obviously famous for his series Salad Fingers, Burnt Face Man and Sock, but his best works in my opinion are standalone shorts like Dog of Man and the new Cream. Has ventured into music and some voice work, even doing a voice gig on GTA V.
Honorable mentions:
Joshua Palmer - Zeurel
Don't know what's been up to but he occasionally tweets frames of works.
Matt Jolly - Krinkles
Can't draw for shit but his Madness series did a fucking huge impact at the time and I still like it. Is now working on a Madness game.