I'm going to buy one of these from Costco for $199.99. I'm not quite ready for it (well, my space in the basement isn't ready), but I found out today that when Costco is out of 'em, that's it, so I need to get one now while they still have them.
I plan to put some 2x8's or 2x10's across the bottom for a shelf, then add some 2x4 cleats across the uprights with some more 2x8's or 2x10's across those for another shelf. Might even put a plywood back on it to seal the back side up, to keep things from falling off the back of the shelves and to make it even sturdier. It's very sturdy and heavy as it is, but more is better.
This will sit up against a wall in a corner, and I've got shelving to put up on the wall, and a Kennedy machinist's tool box for the benchtop too. I've got plans, just gotta get the basement area ready.
http://www.whalenstorage.com/products/workbench.html