It's 3.5 that has KDE.
At Login(lightdm) right next to your name is a circle, most likely with a K in it, click on that circle and a list of sessions will pop up.
On 3.5 you also have XFCE, LXDE, Gnome Fallback(Classic), and Unity. Technically there is also Gnome 3 and Cinnamon but I haven't had much luck with them. If this is 3.5.1 you also have Mate in the Session List which works.
You also have XBMC.
You could also try 3.4 Lite which is just Mate which is more along the lines of the traditional Ultimate Edition look and style.