I liked Delphi's anchors. They were extremely simple, visually defined, and met all of my layout needs.

Those were nice because you would start with floating elements that you'd move around with the mouse until you'd figure out a good layout and then add the anchors at the end and make it all flexible. Delphi was all about having a smooth progression from mockup to prototype to production. Compared to it, current web workflows are outright retarded.