My most beautifullest WWII tank is still (and will probably always be) the Panter, but since that one got drooled on more than enough in this thread already I'll go with another choice. When it comes to design I'm heavily german-biased, they had a knack for combining design with engineering.
I always had a soft spot for the Skdfz 222 (armored scoutcars are allowed right?). It looks cute, but still tough and all the weird angles in its design make it look quite futuristic. The 20MM gun is perfect for the overall dimensions, the previous version with the MG just looks a bit weak.
The long barreled PIII-J comes in close second. I dunno, that one just has "classic tank" written all over it. And, although it's boxy and the bolts sticking out make it look like a shrunken battleship, I kinda like the Cromwell too.
There are more ugly than pretty tanks, so that choice was harder. The Churchill, early Shermans, jap tanks (altough the Chi-ha looks okay), etc., all range from butt-ugly to uninspired at most.
Okay, with the Churchill I must admit: it looks like the Brits at least tried to design a proper ugly tank. Kudo's for that.
But one of my personal ugliest is also german by the way: the Märder III.
Boy oh boy, just look at it. It looks like it'll fall apart the moment you touch it. The Marder I is also kind of funny looking, but in a good way. The III is just a big fail.
