Russ
Istar
For sword shape, form follows function and there is no 'best'. The sword you want will depend largely on preference and time period. Against a combination of plate armoured and unarmoured opponents I'd take a European longsword for its utility but again, that's just preference. You'll use a different style against an armoured opponent than an unarmoured opponent. At the end of the day the best style is whichever one doesn't get you killed.
I would thoroughly concur with the opinion that the european longsword (using the word properly) as the best "all rounder".