My life is so boring I have to live vicariously through you! Try this on for some ideas. The laundry gets its own "area" which includes storage for all the soaps and junk associated with it. You can put cabinets overhead and still have room for more storage. This could even be closed off with a door. Your party guests would just hang a left at the bottom of the stair landing and be hit with a minibar and room for 6 or so arcade machines. Since the room is long, I think it works better to have your stairs enter in towards the room. Just some more ideas for you. (God I wish I was in your shoes.)
Ok I'll throw my 50 cents worth of advice in there.
You are going to have to decide if you want a bar, a home theatre, an arcade or a laundry room. There isn't enough room in that space for all four, you could probably get away with three, but just two would be better.
DNA has the right idea, hide the washer and dryer cause those things are ugly. Put a mini bar where the washer and dryer were. Imho that's all you need. I would then expand the theatre section out to where your other bar was and make one big room. Why? Because without walls you have a lot more space. You can line the back with cabs, some tables, whatever. Walling off such a large space into so many tiny compartments means you are stuck with that floor plan until you decide to remodel again. With a more multi-purpose common area you can play around a bit more as the years go by. For example, your current layout couldn't accomidate pinball machines if you decide to get some later, but if that whole top area was one giant room instead of two, you could line the back with em and still have room to spare. You can do it the opposite way as well, ditch the bar and make a huge common area with the theatre as-is.
The only reason I mention all this is you put "gameroom" first in your description and yet in your layout they look crammed in there as an afterthought. Of all the things down there, games are going to need the most dedicated space. Remember, you have to take the depth of a game and double it in your layout, so somebody will actually have enough room to stand in front of it and play it.
Also something that might save you some space is to reduce the size of that media closet. If those cabs are to scale it's something like 4 1/2 feet? That's crazy. You need two feet max. You don't have to walk inside afterall, you merely have to be able to reach inside. I can't think of any home networking or home theatre equipment that is more than about a foot and a half by a foot.
I'm also wondering why you feel the need to hide the electrical box. The ac and heat sure, that makes sense, but if the box is flush mounted, hang a poster in front of it and you are done. Again, getting rid of some of those walled off areas just gives you more options.
Right now the room looks like it's trying to be four things at once, which I guess it is. You need to pick a theme and stick with it. Personally, I'd go with a home cinema..... a lobby with a small concession stand (or bar if you must) and arcade machines when you enter and a theatre in the back, but that's just me.