300D for it's historical significance
5D2 - another historical camera, signified the convergence of still and motion
1Ds as the first practical full frame DSLR (unfortunate to the Contax N Digital which is the 1st but lack of a good raw converter that it is more or less a TIFF or Jpeg machine, I owned one, but a sad end)
1D4 - just a camera of many refinements
I would prefer the "Shoot great video with your Canon DSLR"
A long time Canon user who used all the above!