Which Linux version is more stable?

Debian is far more stable, but it requires a bit more of knowledge. Ubuntu releases a new version each 6 months, Debian once a year, therefore it's much more tested but it doesn't provide the latest version of every application. But don't get me wrong, Ubuntu is great (I'm a member of the project), though it lacks of stability sometimes.

ubuntu is very good for desktop and server purpose.But i personally like redhat server for server purpose.Most of the companies using redhat linux server and suse server for their company needs.Each version has its own versions and editions.Ubuntu is stable comparing with other editions.It is also user friendly.

I would say Ubuntu and Fedora are the Most stable out of all the options out there unless you are good with programming and Unix command line stuff then any Linux will be pretty nice to you. I would say if you are new to Linux go with Ubuntu as it has a big community and has gotten companies like Dell to get behind it and make some computers that come with Ubuntu Preinstalled. I would also suggest that you go with an LTS version as these tend to be a lot more stable than the non LTS versions. Ubuntu is designed to be as easy as possible for a person who is new to Linux but you may find some good things and some bad things about it. As well depending on your computer driver support might be hard to find it all depends I would suggest creating a Live DVD or CD and trying before you go on installing it on your PC.