My friends got me hooked on a game called Clash of Clans back in December. I initially started playing it to "hang out" with friends, and I've grown to really enjoy the game. I know I'm kind of late to the game, as some friends have been playing it for awhile, but that doesn't bother me. I used to play World of Warcraft a lot, which requires you to physically sit at your computer. The thing I like about Clash is that you play it on your phone (or tablet). You don't need to be physically stuck inside your house to play and check on the game.
My friends and I used to play World of Warcraft for hours on end. I could never join a "raiding" guild (basically a team of people assembled to fight super hard monsters in the game), because I couldn't devote 3 nights of week of sitting at my computer for 2-3 hours. I have other stuff going on. With Clash, I still get to play a game with my friends, but I'm not stuck in my house.
The other thing I like about it is that if you have a smartphone that was made in the last 3 years, you'll have no problem with playing the game. I never played World of Warcraft on a super nice computer, and a lot of my friends played on nice computers. Clash is a level playing field for game performance if you have a smartphone or tablet.
I don't play a ton of games on my phone, but Clash is definitely one of them.