i have had good success in running Open SuSE. Currently i'm on version 11.1, about to upgrade to 11.4 when it is released next week.
As you have more experience with the Windows Desktop, i strongly recommend that you use the KDE environment rather than Gnome. While KDE does use more system resources, it is far more highly configurable than Gnome.
There is an Ubuntu version called KUbuntu.
As for software deficiencies aside from gaming (where Windows is to this day and for the forseeable future the superior system), can you replace those applications with Linux equivalents?
Perhaps give us an example of what software you speak of.
I"ve been meaning to try KDE again - I used it years ago under Solaris and liked it, but somebody else mentioned Gnome was superior to KDE so I went with Gnome this time. For the most part I connect to Linux/Unix via putty and never see the graphical interface.
I've never played games on Windows - just doesn't appeal to me. The software I mentioned is Logos Bible software. I have a lot of money tied up with Logos and can't part with it, so I have to keep a Windows box for now just to run Logos. I might try setting up a Windows VM under Ubuntu...