Pair a game with the right memory, and even stressful games become comforting.
http://www.nintendoworldreport.com/extralife/34889
I talked with a friend about the Nintendo puzzle game Dr. Mario, which is one of my favorite games in the genre, a while back. I mentioned how, similar to how Brain Age presents Virus Buster, I enjoy playing the DSiWare version of the game before I go to sleep at night. Generally, I play one level and then peacefully go to sleep right after it. He was somewhat flummoxed by my claim, citing that Dr. Mario and most other puzzle games, don't really relax him.
I spent a long while thinking over that, because our views on Dr. Mario are diametrically opposite. Then I remembered why I even play Dr. Mario now, recalling an incident in my life that arguably had the greatest impact of any other incident ever. It was the first weekend of my freshman year of college when I first met my wife.
As the story goes, I fortunately was wearing a Super Mario Bros. T-shirt, and she, equally fortunately, had a roommate who brought an archaic TV that only had an RF Switch. So she had a Nintendo 64 and a Super Nintendo and no means to play them. Naturally, we wound up in my dorm room playing GoldenEye, Tetris Attack, and Dr. Mario. (Note: It didn't get dirty from there. At the time she had a boyfriend, but that's a story for another time, likely not in this venue.)
Before that night, I had played tons of GoldenEye and my fair share of Tetris Attack. However, despite owning a copy of the game on NES, I never really played much Dr. Mario. That night, she mopped the floor with me, starting a long, loving Dr. Mario rivalry in which I've won maybe 10 games out of hundreds.
I never cared for Dr. Mario prior to meeting her, but afterwards, it became a comfort game. It's why I play it on planes when I'm travelling without her. It's why I play it before I go to bed when I'm not with her. This is super sappy, and likely a little bit corny, but the only reason I play Dr. Mario is because it reminds me of my lady. I can only hope she plays Super Mario RPG or Punch-Out! when I'm not around because it reminds her of me.