Rockstar - Working on GTA VI. These guys always push the consoles to the limit. Huge man power. In terms of tech and visuals and always near or at the top of the game.
NaughtyDog - Supposedly working on TLOU Remake (rumor) and a new IP. These guys have released some of the best looking games in each respective generation. Some of the best animation, rigging and mo-cap I've seen in in-game models and cut-scenes.
Santa Monica Studios - GoW Ragnarok (Crossgen), working on on new IP, no announcement yet - so most likely due in a few years next gen only. Similar to ND.
Ninja Theory - Hellblade looked fantastic, as is arguably on the best looking games on last generation consoles. HB2 looks crazy good thus far.
CD Project Red - We already had a taste of 'next gen' on PC with Cyberpunk 2077. Visuals and tech the past 2 generations have been up there with the best - though Cyberpunk was quite poor in terms of polish upon release.
Playground Games - Worked on Forza Motorsport series - some of the best looking visuals in racing games. Working on Fable.
The Coalition - Worked on Gears 5. And with Epic to get UE5 demo optimised for Series consoles. Likely working on Gears 6.
I'd put Quantic Dream down though their next game (Star Wars Eclipse) is a cross gen/cross platform game so.. maybe not.
I would add Insomniac games and Guerilla on the Sony part. The successor of Horizon Zero Dawn will probably a technical masterclass. Also Insomniac have shown to be getting better and better at mastering the PS5. Perhaps 343 will also master the series X fully with the new hwlo installment, they have the potential to do so. I don't think CD project Red will really maximize the potential of consoles. The console releases tend to be afterthoughts for them. The Witcher 3 had plenty of problems on current gen consoles at launch.