1) Sherman. Automotively what everyone wanted, also a balance of qualities, AND fit on a Liberty ship (and LST). Lots of great kits, and a kit-bashers dream.. Dragon's DS tracks are great, accurate and quick.
2) T34. Design ahead of its time, eventual reliability, fit on bridges, adaptability, lots of kits....... sounds like a Soviet Sherman. Friuls make even the old Tamiya kits look good, kind of like Tommy Lee Jones' black suit.
3) Cromwell. First British tank that could keep pace with it's own support chain without breaking, and Tamiya's kit is a dream. Bolts? A pin washer's dream.
4) King Tiger, just for the size, and the kits offer a huge painting "canvas". Also look great with friuls (as do the T34 and Cromwell. I'm a Friul junkie).
5) M3 Medium. "A tank? What's that? Sure, we can build LOTS of them." It taught the American rail and auto industries how to build the Sherman, and lots of tankers trained on it, without having to spend ALL their time fixing them. Tamiya needs to re-do their kit, but it looks good enough to get the idea.
6) Pershing) Excellent Tamiya kit, looks good with the Friuls, and the powerplant layout (rear drive, rear engine) that's still in use today. Also first US tank that could be truly respected by opposing crews.
7) German MkIV. Workhorse, lots of mods/marks/ausfs, will look good with Friuls when I get around to building one.
8) Churchill, just because it looks like a WWI throwback, had enough armor to be appreciated by its crews, AFV Club kits are great, Friuls...........
9) KV1, Trump kits are excellent, Friuls, painting possibilities.
10) JS1. Tamiya kit, Friuls, Berlin urban settings. Plus, the fenders seem not to last very long, making for an interesting look. Russians are still lousy drivers.
Given the nature of this forum, my list is as much kit review, in a very general way, as it is a list of personally signinicant tanks, but there ya have it.