Nexenta was the first OpenSolaris that caught my eye, and since then I've tried a few others. There continue to be some annoying driver issues, so I've given up on trying to install OpenSolaris directly on hardware, and instead have opted to using VirtualBox. My most recent installation was of os200805, and I have to say, its really nice.
I wish it were available pre-installed on some cheap notebook - I'd definitely give it a run. Supposedly it will be available on some Toshiba laptops at some point, but I'm not holding my breath!