I can't ever get comfortable enough while lying down to play games. I prefer to be sitting upright. For a while I had everything rigged in the living room, with a crazy long VGA cable running through the office wall to the TV so I could play PC games. My living situation has since changed, so I went out and bought a 24" TV/Monitor and now have everything installed in the middle room/office now. Years ago I dropped the dollars to get myself one of those fancy office chairs with awesome lumbar support and that hump on the seat edge that keeps the circulation in your legs going. It's getting kind of worn out now, so within the next 6 months I'll probably try and get another. I like my new setup fine. I can just use the headphone jack on the Monitor/TV and crank shit up without bothering anyone. I don't ever eat while gaming, but I do like a frosty beverage to be close by.
I like handhelds (well, I like pretty much anything that is shiny and makes electronic noises), but I never really play them. I always buy them and then end up selling them off a few months later, barely used. I don't travel much, and if I'm sitting around the house I'd just rather play PC or console games. Same with tablet games. I used to buy a lot whenever they'd go on sale, but don't ever spend more than five or ten minutes with any of them.