A lot of the usual games people are mentioning (Overwatch, Hearthstone/Gwent/Card Game), but also quick arcadey type games and rogue-like games such as Binding of Isaac, Super House of the Dead Ninjas, Downwell, Super Meat Boy. Things like that are really good for quick play sessions, along with a lot of mobile games.
I very rarely play for under an hour but I find platformers (Lego games, Yooka laylee, rayman...) & kart racers (Mario, CTR, sonic transformed..) work really well in quick bursts
I guess anything that has short self-contained 'levels' without much story would work
My favorite thing about most matchmaking is that you can do it in short increments. I like to get on and play a couple matches of warzone and swat in halo 5 in the morning before work or before starting my day.