Best distro for development?

[saistain]

Which distro do you think is the best for software development?

I'm most looking for a complete development package with all gnu tools, libraries kernel headers, etc, and also incredibly important for me is changing versions - not only ease of upgrading gnu tools to the latest version, but to keep a back date catalogue of previous versions of gcc, older kernels, complete set of kernel headers for each kernel version, etc.

I need such an OS with complete set of libraries, etc and where changing versions is not a pain, because compiling older software, and cross compilers is completely hit and miss, and on my current OS (ubuntu 5.1, with only the libraries that's on the CD) has been a nightmare and I'd like to start fresh.

Any suggestions as to which distro I should get, and also any input on how I should set up the OS to make life easier for me will be greatly appreciated.

Ty

[RobinVossen]

In my eyes Gentoo.
since everything is compiled in that one.