Hi Xinix,
Welcome to the forum.
You'll probably get about as many different suggestions as you get replies, but as a realtive newbie to Linux let me try to take a shot at this.
There are several distros that shoot for the recent converts from Windows. These include Lindows, Lycoris, Xandros, SuSE and others. Let's call them "soft core" distros. Then you have some "medium core" distros. Mandrake, Red Hat, and others.
Slackware is definitely, from what I've read "hard core" Linux. I can't speak from personal experience since I'm a realtive newcomer to Linux and only experienced in Red Hat, but from my reading, that's the score.
There are hundreds of distros, try a flavor and have fun. If it's not to your taste, blow it away and try another. It's not like it will cost you much more than your time
FWIW
Jim