If you have the room and can control your light, I would consider an Audio Transparent screen. You can make this yourself too, in the end the expense will be more than the other DIY options mentioned here but I think it is a great option you should consider.
Going AT allows you to put your speakers behind the screen, where they belong, being able to accommodate identical L/C/R speakers without having to worry about placement issues with the center channel and in my opinion, I like the look of a theatre where you can't see the speakers at all, at least the front sound stage.
The DIY options for AT screens starts with the Sun Shade material Sheerweave 4500 in the Chalk colour.
