Asking a question like this will never give you an unbiased answer. My advice, try them all!
Agreed. One man's Ferrari is another man's bicycle. Give them all a go. Running VirtualBox on a base system is a good way to go. However, I suspect you'll stick with Ubuntu 10.4 long term support (most folk do) ; a fine combination of bells and whistles, user support and a reasonable shelf life.
If you want ease of use and an OS that does everything, Win7 is the winner, sadly enough.
If you have a netbook, preferably an ASUS due to availability of open source drivers, then MeeGo is unbeatable, even better than win7. Ubuntu NR has much more ready apps, but MeeGo is generally faster and much more enjoyable.
For a laptop or desktop, Ubuntu is by far the best *nix all things considered. OpenSuse is a good second, but much more cumbersome.
But my favorite OS is puppy linux. It is easy to use when getting used to it and it is a must when you are trying different OS'es and you are constantly repartitioning your hard-drive. It can be installed in no space at all, and after a while you will use it more and more
I was in the same boat - being a long-time Windows user and wanted to try desktop Linux after seeing how awesome Maemo is.
A friend of mine said that it doesn't really matter which one you choose, because all the major distributions are good enough. All of them have their pros and cons.
I chose Fedora and stick to it now.
It is very easy to use and its community is very helpful.
