Trick question... obviously you want to be on 1,000 gram (front and rear wheels combined) low-profile carbon tubulars mated with $150, 200 gram tires. The lowest rotating mass of any possible wheel option, almost impervious to pinch flats, and the tires stay put safely stuck tight to the rim if you have a sudden deflation.

However, if you are carrying loads, or riding in the rain over sketchy roads, you'll obviously have to ride something heavier and stronger than the dream setup I just listed.

Life is full of compromises...