Well. There are other things to think about besides just the tank. If you have any kids or any pets with claws, or ever plan too- GLASS! definately! Acrylic and Glass both have their upsides, as you have seen from the other 2 responses. I prefer glass because the RESALE is much higher (check ebay to see the resale statistics of glass vs. acrylic) if you arent settled in, acrylic would be easier to move, and less susceptible to breaking, though I have moved 3 large glass tanks (just need help to carry them!) If this is your first tank, I would go for glass. If you develop slime algae or coraline algae, it will definately be easier to remove from a glass tank, with less fear of scratching. Scratching can also occur in the bottom and sides from the substrate and live rock as they are shifted around. The choice is yours, but I personally recommend glass for the longer haul. You can always try a very small acrylic tank (maybe set up a micro-reef or a fish only saltwater desktop tank) and see how the acrylic suits your liking in terms of maintainence before you go larger.
Best of luck! Hope to see pics of your tank sometime!
Daisy