The worst...

Grimbru: The AMX 38 and 40. Honestly I did not have a great time grinding xp on these two...   I went down that line for tanks like the ELC AMX and onwards... fast and fun tanks with a 'better to burn out than fade away attitude'...    They do indeed have some pretty troll armor for the tier though. It just was not the reason I went down the line in the first place.