Get your pitchforks out. This is a thread for people to vent.
Anyway, I'd have to say Konami by a wide margin. Say what you will about Capcom, they're slowly starting to turn things around. RE7 was just released to widespread acclaim (and rightfully so because it's a damn good game), MvC:I looks good, REmake 2 is in the works, and it's very possible DMC5 will finally be announced sometime later this year (Hideaki Itsuno teased a new game reveal in 2017, very likely DMC5 or Dragon's Dogma 2). Square-Enix has also made a few headscratchers over the last couple of years, but then they started doing good things again (the Avengers Project being a huge one). What has Konami done besides royally fuck up over the last 2 years?
Between their holding beloved IPs hostage in favor of pachinko machines, mistreatment of staff, blacklisting Kojima, butchering The Phantom Pain's story, turning TPP into a microtransactioned mess, cancelling one of the most hyped survival horror games in years (Silent Hills), scamming Steam PES players with a last gen port using PS4/Xbox One visuals in advertising (that's fucking illegal), turning Metal Gear into a generic survival zombie game (Metal Gear Left 4 Dead, err, I mean Survive), releasing a $50 budget game with offline lag (Super Bomberman R), etc., no company has done more to make me revile them in such a short span than Konami. Seriously, can anyone name a single thing they did that WASN'T a gigantic middle finger to gamers everywhere since 2015?
In the legendary words of Jim Sterling, "Konami is Konami and Konami is the worst." Or, to quote GDT and the words of millions, "#FucKonami."