If you want you can make a different poll about whether or not a clean rider can beat dopers by being the strongest on the day. But that isn't the question in this thread.
Obviously, there is another thread about the same topic, but it is stuck in pedantry with a refusal to discuss the meat of the issue.
The thread Dan Martin - "Now I know you can win clean" is obviously about Dan Martin, (and turned into a general DM discussion thread).
Let's talk more generally. What races can a clean rider be able to win, in this peloton?
Cheat Sheat:
Grand Tours
1.WT (Monuments)
2.WT (Stage Races -GTs): Pais Vasco, Paris Nice, etc.
1.HC (Other Classics) Scheldeprijs, Paris - Tours
2.HC (Other Stage Races) Tour Of California, Tour of Turkey
1.1 (Lesser one-days) KBK, Chrono des Nations
2.1 (Lesser Stage Races) Women's ToC, Tour de San Luis
1.2 (Lesser Lesser one-days) Tour de Okinawa, Giro del Medio Brenta
2.2 (Lesser lesser stage races) Tour du Rwanda
EDIT: Bad editing on the title. Can a Mod fix it please? And I missed a category for Grand Tour Mt. Stages, too.