If I had the room - which I hope to, in the next couple of years - I definitely have plans to augment my gameroom with more machines. I've been really, really impressed with the driving cabs that have been built over the past while, but what I'd kill for is this:
There's one at our local Chuck E. Cheese, and I've played it a couple of times. The vid doesn't do it justice, but the 'pod' moves with you as you play. So, as your Mech walks, it bounces with each step. If you get hit, the machine moves with each strike. I don't even know where to start with such a build, but I'm sure some of you guys would definitely have some good ideas and input on how this thing works.
Definitely one of the best and most immersive games I've ever played.