My better half hates me gaming on my PC. She would like nothing more than for me to quit!
However, our current work regime means that I get chance every Tuesday-Friday evening to play a bit. Depending on what site I am working at, I can be home by 4:30pm and she wont be in till between 9-10pm most evenings.
Weekends are spent doing 'couple' stuff if we are not working, but if we have 2 full days off together (which is rare) I generally do some gaming for a couple of hours on Sunday afternoon.
The technique I use is to use game time as a bargaining tool. For instance, on a Sunday I will say I am going to go on my computer for a few hours, but then I will cook dinner. The basis is that she lets me do something I want to do, then I will do jobs that she wants me to do and vice versa.
Its odd because if I suggest playing lego indiana jones on xbox she will play that with me all night. In fact when we first had it, we played from 10am till 2am the following morning for a good few days. The difference is that she can join in and be part of it. I think the key to her acceptance is getting her involved, but she only plays games she can do (IE simple ones). FPS games, which is what I love, are lost on her because she just cant do them. She also loves kinnect gaming, and wii but for some reason she just hates me PC gaming.
She feels that PC gaming is anti-social, and I understand that because my PC is in the spare room upstairs and I mostly play online FPS where I wear headphones and it is not something she can play with me. I am thinking that moving the PC downstairs might be an option but I doubt she would have it.
Its about compromise and being reasonable. I was a PC gamer before I met her and PC gaming is one of my main hobbies. Motorbikes is the other. She has had to accept that fact, but I have also had to accept that being in a long term relationship means I have to tone down the gaming. I'm not a single man living on my own that can spend time doing as I please anymore. Indeed the hard part in general has been adapting to that fact when I was so used to doing what I wanted when I wanted. But we have lived together for around 4 years now and we seem to be doing ok. We have a good balance.
Just on a side note, her aversion to PC gaming has been amplified by the fact that she has no hobbies of her own. So when I am gaming she has nothing to do, other than sit and watch TV or browse the internet. I think in our situation that is the main problem because she feels bored and lonely. I have tried to get her to look for hobbies to get into but she says her hobby is 'us' which I hate and feel is rather unhealthy. I feel time spent doing our own thing is just as important as time spent together, otherwise it becomes stuffy and we end up throttling each other!

The other problem is that her passion, and her actual only hobby, is what she does for a job day in day out, so she is not interested in doing it on her days off.
Cheers
Buff