I'm more into twitch games that I can pick up, play with for a bit, then put back down again. (Comes from the hours required for the job, and having little kids...) I've been into MAME (Multi Arcade Mission Emulator) for awhile. It grabs the ROM files from the old arcade games (Asteroids, Space Invaders) and puts them into an on-screen playable emulator.
Nothing like playing the old games from the 80s. And, I can "feed a couple of quarters in", play for a few minutes, then walk away without getting sucked into playing for hours. It's a pleasant, brief distraction.
COD online can be as quick as you like. I sometimes drop in for about 10 minutes because I have to admin the server (kick out problem players). I can jump in, shoot a few people, watch for idiots and get back out. My son started playing it when he was 8 so even kids can pick it up.
The sniper servers are very slow-paced which can be a welcome relief. I wish I had it when my kids were really young. When my daughter was 2, she would sit on my lap and watch me play Harpoon, yelling “BANGO” everytime a missile hit a ship.