Ubuntu, even though I haven't used it since Hoary Hedgehog (whew, feels like forever ago!) - it's clean, runs well, and there's more software out there for it than you will ever need. Ubuntu was what led me to AbiWord, for example - very slick piece of word processing software. I didn't miss Windows one bit, and I could even 'mount' my Windows hard drive so I could view files from it.
There's no such a release! Hardy Heron is the codename of Ubuntu 8.04, which is still active ( LTS ).
Ubuntu does seem like a nice choice, though if you some more titles, perhaps more obscure than the most popular ones... there are sites that list similar stuff like this. Take http://alternative.to/Windows_7,29200570 for example... quite a list, under the article.
I recently switched from ubuntu to linux mint. It's also based off debian, so the same packages are available. I found it quicker and some stuff was easier to configure.
Mac 10.6 all the way. 2 years ago I would have said Ubuntu, but since owning a MBP i've fallen in love.
You can try Linux, but I still think as a personal desktop , So far windows is still very good, There are a lot of developers to develop software for windows.
i would like to recommend you for linux.ubuntu is one of the most popular os which is launched my linux.i think if there is any alternative name comes after windows than it must be linux.