Personally I'd go for the Modern option his cenurrt design balances classical references with a sleeker update. As opposed to the Adventure days where he was presented as cool', the shiny plastic' Sonic Heroes era and the humanoid hipster' of '06, the Unleashed/Colors model (which seems to be the one shown here) takes the best features of both eras. His quills are slightly longer but not too long (06 had the latter issue), his eyes are expressive without being overly aggressive (SA days), and his legs are longer than classic Sonic's but not noticeably so (06 problem, again). And he's not shiny plastic, which is always a good thing. In short, a near perfect model of the Modern Sonic, and a nice contrast with the pot-bellied classic.