Found this nice graphic of Spacecraft size comparisons. A notable point to the graphic and capsule history are the number of flights of Soyuz in comparison to all others. It has definitely been the most successfully flown spacecraft. Another point is that the Dragon has a capability of 7 astronauts (not 6 as the graphic suggest) and the Rus has 6.

The first crewed flight of the Dragon is expected sometime in 2015. Here is a great graphic on the SpaceX Dragon manned capsule.More info on the Rus or PPTS can be found here and here

Click to enlarge

Click to enlarge