I have had a few glass tanks, and a few acrylic. Glass is nice cause its easier to keep clean (because you can scrub it with no worries of scratches) and in the long run will stay clearer for longer. Acrylic is nice because it is light and easy to modify.
In hindsight, if you have deep pockets and are building your final dream tank then go order yourself a custom starfire glass tank from a reputable builder. Otherwise, go acrylic.