The American counterpart, Science , has little content available without a fee and did not make the list. Cells Alive A commercial site that displays an incredible diversity of stunning graphics, both stills and movies. All those biochemical pathways you have to memorize,organized well into metabolic groups. The Online Macromolecular Museum Macromolecules in 3D display. A browser plug-in is necessary, but it is worth it.
Rotational imagery give one a different perspective on molecular events.
Cellupedia A very professionally designed site with extensive content on cellular anatomy and processes. On-Line Biology Book Chapters in several areas of biochemistry and Cell Biology. The Biology Project Interactive learning site that contains areas in both biochemistry and cell biology. The MIT Hypertextbook A well established resource with extensive material on biochemistry and cell biology. A good starting point for genetic discovery.