In general I'd have to say that you can't beat a proper 5.1 (or greater) system. However, some of the top end pseudo surround systems are pretty good. They work by 'bouncing' sounds off of the walls, as such you'll need quite an empty room for maximum effect. I suggest you get a 5.1, it probably won't be as inconvienient as you imagine...
Have a look at KEF's Instant Theatre for an absolute quality pseudo surround system. It looks the dogs and sounded great when I heard it at full blast in my local shop. Over a grand though, so it's serious money!
I've heard one or two of these psuedo surround systems and they are quite impressive, if you sit in exactly the right place. There in lies the problem; you need to position the speakers and yourself so precisely that it becomes a huge hinderance. I think this is a technology that will be perfected in the future but for now a proper 5.1/7.1/9.1 etc setup is probably the way to stay.