Before anything else -- how could you NOT list the Wirbelwind?????
After the Wirbelwind, I would like to see the earlier armor filled out before adding a bunch of late war uber-tanks . . . or at least armor that would be significantly different than what we already have in the game.
Pershing -- in game terms, not too different from the Tiger.
King Tiger -- eh, very rare, I personally could do without it.
Comet -- again, in game terms, not much different than the Firefly.
Crocodile -- no need for a flame-throwing tank.
Churchill -- many variants to choose from. Slower than the current set, very heavy armor, relatively weak weapon -- would at least add variety.
Panther -- would love to see it, heavily perked.
Stalin JS-II (or IS-II) -- Large HE shell, but again, hard time seeing the difference in game terms vs. the Tiger (except for the inferior optics).
Sturmtiger -- not really. I thought it was more an experimental vehicle.
M-18 Hellcat -- Sure.
StGIII -- I would prefer the Hetzer myself, but there are a wide array of assault guns to choose from, and the StGIII would be as good as any.
M5 Stuart -- Yes.
If I ruled the universe, aside from immediately smiting my enemies, I would add a few variants of the Sherman first (early M4 with the 75mm, M4A3 with the 76mm gun, one of the 105mm variants, perhaps the Calliope) because you get some decent variety off the same chassis.
Then I would add a few more PzkwIV variants (C, D, and F versions) for the same reason.
Then maybe the T-34/85.
Then the truly early war tanks such as the PzkwIII, Pzkw 38(t), Matilda, Crusader, BT-7, T-26, S-35, Char-b1, M-3 Grant/Lee and M-3 Stuart. . . not necessarily in that order.