We should do it by sales of previous consoles
A = Playstation
B = Gameboy
C = Nintendo Entertainment System
D = Sega systems
E = Xbox (?)
F = Jaguar
And for +/- it is easy.
A + = Playstation 2 (sold more than 1)
B - = Gameboy Advance (sold less than original + Colour)
C - = SNES
E + = X360
F is just F no +/-
http://www.vgchartz.com/games/userreviewdisp.php?id=261
That is VGChartz LONGEST review. And it's NOT Cute Kitten DS