I found every German tanks pretty standard. Their design are all plain, and very well matching the exact proportion about my imagination of "how a tank should look like". The most balanced aspect in the design for me is Panther tank, especially the Ausf.G model. It has the most "tank look" of all WW2 vehicles IMO. Tiger I is too plain, too overrated, but it stands clear as a "tank look" standard. So does other country's tank that match this proportion, for example Cromwell tank and Crusader III or Russian T-34s (somehow i don't like model 42's turret shape, the 39's mod is good, and the best is T-34-85). I think it would look more proportional if T-34's turret placed a bit rearward.
The most ugly looking of all panzers for me is Panzer III, it is too plain, too wide for its proportion, looks like a short obese guy that is out of balance. It has a kind of "boring charm" for me. I rarely take them when playing FH2.
The most beautiful? I think Jagdpanther is cool, it has big slope armor, makes it look slick, and forward firing MGs! One of the most task-balanced cannon-carrying vehicle of WW2 IMO.
The ugliest? Apart from all the funnies (modified tank hulls), specialized vehicles, and tank concepts... the ugliest tank that is generally deployed in service is Char B-1 bis. That tank has a cartoon-ish look and its thick armor can be observed from its looks. It looks like that it is a design from another dimension or planet. If i were facing this tank, i would have smirked because they look more like a toy than a fearsome battle machine. Make no mistake, I do know that in the early war, even the Germans feared these tanks for their armor thickness. But i judge it here only by its looks.