1. Rainbow 6 Siege. - If the community for this game wasn't comprised of just the most horrible wastes of matter ever, it wouldn't even crack my top 5, but knowing that if I miss a shot, or miss some guy in the corner I'm going to get 4 DM's from 10 year olds telling me to kill myself definitely adds a level of stress that no other game does for me. (For the record, I have message notifications turned off now, and only accept messages from people on my friends list, but it's like how you still have nightmares about high school for decades after you graduate...that feeling is always there).
2. Overcooked/Overcooked 2 - Just because it's like the one game my fiancee likes playing with me, but also, we had to stop playing at some point before one of us said something to the other that we would not be able to take back.
3. Bloodborne - Obvious reasons, but oddly I find the Dark Souls games to be more calming experiences overall. I'm sure it's something to do with always needing to be on the offensive.
4. Old Adventure Games - Any of them up until around the more modern Telltale stuff. I love the stories and the relaxed pace, but I also just hate being stuck. If I'm going to list a game, we'll say Day of the Tentacle, but any of those old LucasArts/Sierra adventure games just stress the hell out of me.
5. Rocket League - Easily my most played game this generation. And I'm pretty pretty good at it. It's almost stressful for the opposite reason that RB6 Siege is, but I'm also not a jerk, and I've never sent a DM to a disappointing teammate, no matter how badly they blew it. It just sucks when I'm carrying a team the whole game, and all they have to do is sit back and not let the other team score, and then they score an owngoal, and you just want to rage.