I want to go Linux, what is best for a beginner?

10 years of using Windows, and they're running slower and slower, using more and more of my system resources, I feel I'm ready to give Linux a try. But I don't know anything about Linux. I'd like a OS that offers same or similar visual effects of MAC OS or Windows, and the familiar windows-style... show more 10 years of using Windows, and they're running slower and slower, using more and more of my system resources, I feel I'm ready to give Linux a try. But I don't know anything about Linux.

I'd like a OS that offers same or similar visual effects of MAC OS or Windows, and the familiar windows-style taskbar/start bar.

I have vista x64 installed on my computer, could I have two OSes installed and just picked what I want at advanced boot options menu?

what is the most compatible version of linux/unix with PC-compatible programs like Adobe CS3, Steam, AutoCAD 2010, VLC media player, Solidworks 2009, and MS Office 2003?

Are there any Linux x64 versions?
brief system specs:
Intel i7 920 quad
MSI X58 Platinum
6GB DDR3 1333
1.5TB primary hard drive capacity
Onboard Realtek sound and G-bit NIC
DVD-RAM drive, 16x?
IBM compatible mouse, HID keyboard
nVidia GTX285 1GB graphics
5 answers 5