I assume by "flavors of Linux" you mean distribution? In this case you may wish to check out Red Hat-based ones (Red Hat, Mandrake, etc.), SuSE, Lindows, etc.
Really, any Linux distribution can be made to be as gui-"heavy" as Windows* -- just look at KDE 3 and GNOME 2. There are more slim desktop environments, too, like XFce. Also the slimmer window managers like Blackbox, IceWM, Ion, Pwm, etc. are all worth checking out.