1) Nowadays, most guys grew up with video games.
There are two types of Wii owners: the "I've never bought a console till now" non-gamer and the "I can't believe I can play through Ninja Gaiden II again on Virtual Console!!" hardcore gamer who wasted a whole summer of his 12-year-old life trying to beat the game. The same strong sense of nostalgia you get when watching Scarlet kiss Rhett is what your gamer feels when he races through Super Metroid for the 74th time in less than three hours so he can see that Samus chick without her battle suit on. So no need to ask if he's going to buy Metroid: Other M when it comes out in 2010. You already know the answer.
2) It's a great way to relax and yet be engaged.
My coworker Max tells me that TV seems like an even greater waste of time than video games, where at least you feel like you're working toward something and improving your skillz. "But how can one muster the required brain power after a grueling work day of crunching numbers?" I asked. Nah, just toss in a competitive first-person shooter or slower-paced role-playing game, depending on the available mental resources. And as Steve put it, at least you know exactly where your guy is at night. ^_~
3) Keep in touch with family and friends (without those awkward pauses in conversation).
I probably should've put this one higher on the list because almost every gamer I've talked to has offered it as a reason. Derrick left his entire extended family back in Little Rock for work, but once a week, he dons his Xbox headphones to play Call of Duty with his brother - and feels like he never left home. My husband K hasn't seen his childhood best friend in forever, but the years melt away when they both log on with a copy of Crackdown. Girls, think of it as the male version of calling your mom everyday.
4) It leads to a great career in the military.
Have you seen all those TV ads that show pilots flying unmanned aerial vehicles for scouting out enemy positions? That's right, they're targeting the gamer audience, hoping to entice them with playing a Flight Simulator for money. So don't scoff at your boyfriend's dream of being a professional video game player; those mad button pushing skills may rake in the big bucks yet. ^_~
5) Sometimes a guy just needs his cave time.
As much as I love to watch my husband play games every night, most men have a regular need for cave time. Since his work schedule is later than mine, the perfect time to play games without interruption is when I'm asleep. True, that means I go to bed most nights with no one to warm my feet, but the trade-off is totally worth having a husband who now has greater Reserve Tanks for lovey-dovey time when I'm actually awake.