I don't think Milito should be in the top five to be honest. Milito was fantastic last season, and he indeed did decide most of Inter's trophies, and was probably more consistent than Sneider too. But, after mid may, what did he do?
He barely played in the World Cup, and this season he's been mostly injured and when he has played he hasn't been all that special, granted the whole team barring Eto'o has been that way this season. Still, i'd say that if Milito was worthy, then so would Robben be.