Which one is best for asterisk

I am new to asterisk, want to know which linux OS is best for asterisk to install? I found centOS is the best but could not download it. Is fedora good for it? Can I proceed with fedora latest version?

Most development is done on CentOS 5. CentOS 5 is very similar to a similarly number Red Hat Enterprise Linux. Using CentOS 5, will make it easier to get support and make it less likely that you will need it.

As far as I know, Fedora is older than RHEL, but if it uses a 2.6 series kernel, it should be usable.

CentOS 6, and 64 bit systems are less well supported.

The UK Mirror Service still has CentOS 5 ISOs, so I would assume that your local mirror has them, as well.

The “one” in your subject should have been “Linux distribution” for the subject to be useful.