The picks, and how long a real session takes
Rocket League is the best answer on this page. Free, full crossplay, five-minute matches, and easy enough to explain in one sentence that a friend who has never played can join immediately. Nobody has to be good at it for it to work.
Mario Kart 8 Deluxe is the couch equivalent - a cup is four races and about fifteen minutes, four players locally, and the learning curve is effectively zero. It is the game to put on when people arrive and nobody agrees on anything. Review.
Overcooked! All You Can Eat is the loudest hour you can have with three friends. Levels are a few minutes each, full crossplay across every platform, and a group can walk away after any kitchen. Fall Guys is the free no-pressure version, and Among Us rounds run roughly ten to fifteen minutes, which fits an hour neatly and scales up when extra people appear.
Super Smash Bros. Ultimate handles up to eight locally and a stock match is a couple of minutes, so a room can churn through matches without anyone committing to anything. Human: Fall Flat is the cheap one, and its levels are self-contained enough to stop after any of them.
The Jackbox Party Pack is the pick when the hour includes people who do not play games - one host, everyone else on a phone, a full game in twenty minutes. Review. Apex Legends is the outlier here: matches are longer and it is the most demanding thing on the page, but it is free and a trio can fit a few matches into an hour.
Making the hour count
Decide the game before the night, not during it.Twenty minutes of "what do you want to play?" is a third of your evening. Pick one, tell people, and make the picking a group habit rather than an event.
Pre-install and pre-update. Consoles update games at the worst possible moment. If you know Friday is the night, let the machine do its work on Thursday.
Start with the thing everyone already knows. Learning a new game and playing a game are different activities, and only one of them fits an hour. Save the new purchase for a night with room in it.
Stop at a clean point rather than at a time. Ending after a match feels like a finished evening; ending mid-mission feels like being cut off. The games above all give you that choice every few minutes.
Related situations
If the constraint is that people arrive and leave unpredictably rather than that the evening is short, our drop-in drop-out guide is the better fit. If the hour is a lunch break with colleagues, we have a page for that. And if you simply want something to start in two minutes with no plan at all, games for when you are bored is the shortest path of the lot.