Oh, there's a GUI (for the desktop distros); in fact there are several to choose from. I'm using KDE 4.2; it's this I'm describing as "fast and more powerful than the Windows desktop." There is no GUI for the server versions of Linux I know (they don't need 'em!). The file manager ("Dolphin") is a thing of beauty, far ahead of the versions of Windows Explorer I've seen. Firefox is my browser.
Though once I did (while wiping off my keyboard) manage to inadvertently enter the command to leave the GUI environment and enter the world of pure, hardcore Linux. I immediately rebooted to get back to the beautiful GUI.
"If you can't take a little bloody nose, maybe you ought to go back home and crawl under your bed. It's not safe out here. It's wonderous, with treasures to satiate desires both subtle and gross... but it's not for the timid." Q, Q Who