Here's a good one, courtesy of Runitout in the MPSB thread:
If you could be a pro racer for one day, which day (hence, race) would it be and why?
That's one day... though it shouldn't limit you to one day races, or even races currently scheduled. (e.g., the next time the Tour hits Alpe d'Huez or the Giro prologue in DC or something). Even for me, this is not an easy one, however much restraint it requires not to blurt out "de Ronde!" Honestly, I am torn between a cobbled classic and the last day of the Tour de France. A great race is one thing to experience, but I can't imagine the incredible sense of accomplishment, relief and giddiness that comes with arriving in Paris after the hardest three weeks any cyclist will likely know. Then there are the crowds, as well as the stage battle... a lot to ponder here.