Yes. Actually, it is and has been for awhile now. Though it can be debated that, since it doesn’t have World of Warcraft, it isn’t.
This is unfair really. It doesn’t have it, not because it cant, but because no one has coded it yet.
http://rudd-o.com/archives/2006/10/29/linux-is-ready-for-the-desktop-and-this-is-no-longer-a-debatable-matter/
and
http://blog.linuxtoday.com/blog/archives/061027-072719.html
Link to some articles that recently appeared on the matter of Linux being ready for the big time.
In all honesty, MacOSX is probably the ultimate desktop environment available at present. This is due more to hardware than software. Really, everything that makes OSX groovy is hardware stability and power. Things PCs just don’t have no matter what they’re running. OSX certainly has the market cornered on eye candy that doesn’t break the system resource budget either, something that Linux doesn’t have much problem with, though it’s not in the same league yet… but anyone who’s looked that system requirements for Vista know M$ isn’t even in the same galaxy… they seem to think you should have an industrial supercomputer to have a pretty desktop.
All in all, anyone who hasn’t given Linux a fair try should. None of the distros are very difficult to use, install, or learn. www.distrowatch.com will give you a lot of information to help make a descision… and if you find one you don’t like remember that Linux isn’t the distro, it’s the little file /boot/vmlinuz …. don’t give up, just try something else. Odds are, the distro won’t much matter, they all contain a lot of the same software these days anyway, the better thing to do would be to make sure you aren’t using an application ill suited to your needs. Don’t like the way Evolution works with gmail? Try Kmail, Opera, Mozilla, Pine, etc…
I don’t really know why I’m bothering with this, I think I’m just really bored, and I DID want to share those article links, but felt compelled to give a little context and my opinion.