There are two classes of Star Destroyers that can land, all sharing the traditional wedge shape. The Acclamator class was the one in Episode II and III. The Victory class was larger and disticted by its atmospheric control surfaces on its sides. Images of each ship (including the Carrack and Dreadnaught):
Acclamator class
Dreadnaught class Heavy Cruiser
Carrack class Light Cruiser
Dude, you have WAAAAAAAAAAAAAAAAAAAAAAY too much free time.
This is, of course, the precursor to the flying winnebago in Space Balls...
NERD!