Wouldn't back Canonical stuff
If you want to run a non-mission critical web server on Linux and you want something simple, then Ubuntu Server might be okay.
Don't get me wrong, I really like Shuttleworth and what he's trying to do. But if you're doing anything serious and *you know want you're doing* then go upstream. Debian is much more stable, has a better track record and comes from a commercially solvent org.
I certainly wouldn't want to stick mission-critical stuff on an OS produced by a company that's never been in the black.