The Ikea Jerker. Simply the name strikes fear into the eharts of lesser desks worldwide. It's pretty much the only desk that often has fansites devoted to it - even Ikea's more traditional Galant and Mikael desks rarely garner the attention of the Jerker. It's truly an exercise in simplicity leading to perfection. Take two large rectangular steel T-shaped poles, with sets of screwholes drilled at regular intervals. Add a large desk surface, a fixed full-width shelf, and all of the nuts and bolts to put it together, and you've got the basic Jerker. The kicker, though, is the fact that thanks to all of those holes, you can put any of the components wherever you would like. The customization in accessories is unmatched, too - you could get additional full-width shelving, complete with a height extension kit, CD baskets that hang perfectly in the Jerker's mounting holes, and square shelves on a swinging pylon.
No two Jerkers are alike. Shame Ikea stopped production and replaced it with a 2/3 scale imitator.