Let's see
since 2006 because that's after the armstrong years
Vuelta:
2012 CONTADOR VELASCO Alberto
2011 COBO ACEBO Juan Jose
2010 NIBALI Vincenzo
2009 VALVERDE BELMONTE Alejandro
2008 CONTADOR VELASCO Alberto
2007 MENCHOV Denis
2006 VINOKOUROV Alexandre
Giro:
2012 HESJEDAL Ryder
2011 SCARPONI Michele
2010 BASSO Ivan
2009 MENCHOV Denis
2008 CONTADOR VELASCO Alberto
2007 DI LUCA Danilo
2006 BASSO Ivan
Tour:
2012 WIGGINS Bradley
2011 EVANS Cadel
2010 SCHLECK Andy
2009 CONTADOR VELASCO Alberto
2008 SASTRE CANDIL Carlos
2007 CONTADOR VELASCO Alberto
2006 PEREIRO SIO Oscar
And there is a fair chance that we get a new winner for every GT this year
Sure the amount of possible GT winners is limited compared to the amount of possible classic winners but it's not as predictable as you make it out to be.