I know where you're coming from wakey. I've had a few blow-outs with my wife in the past. We've got two kids, with a third now on the way, but as anyone on my friends list will know, I'm online most nights.
I get away with this by doing as much as I can around the house and with the kids (ages 5 and 3) over the course of the day. I'm happy to put in my fair share to housework and all that stuff, and even more so now because she's pregnant. We usually watch a bit of recorded tv or some episodes from a box set together, with her heading to bed between 9-10pm. Then I get on til about midnight (or later if i'm feeling particularly addicted!).
We try to make sure we have a night out together at least once a month, to actually spend some proper time together. The argument we used to have was regarding how much I'd play the 360, which I would counter by saying she watches loads of Oprah/Come Dine with me/Jordan and Peter/Private Practice/Gray's Anatomy and I don't complain about it! After a couple of big arguments, we came to the arrangement we have now, which works well for the most part, and we spend some proper time together away from any electronic distractions as regularly as we can. You definitely need this I think (not you specifically, but people in general).
As has been said before by other people, gaming ought to be seen by our wives as the most benign pastime ever - would they prefer us to be out boozing with our mates, potentially away shagging some other young one? With our hobby, they know exactly where we are and who we're with, and the worst that can happen is we don't quite get a full night's sleep. I usually find though that a couple of late nights forces me to go to bed early the following night - maybe that's age talking!
A trick I occasionally carry out (which my wife is fully aware of as a ploy, but she appreciates nonetheless!) is, once the kids are put to bed, to run her a nice hot bath, light candles, burn scented oils, etc etc. This relaxes her and makes her very sleepy, meaning she'll enjoy her bath and then go straight to bed, leaving you with hours and hours of gaming heaven.