Ok ok, I'll bite.
Prime lenses-
Sigma 8mm
Canon 24mm 2.8
Sigma 20mm or 24mm or 28mm primes
Canon 50mm 1.8 or 1.4 (I think the 1.4 is worth the extra money, but most people don't, though I don't own one.
Canon 85mm 1.8
Canon 100mm 2.8 USM macro
Sigma 150mm 2.8 HSM macro
Wide zooms
Tokina 12-24mm 4
Sigma 18-50mm 2.8 EX DG (Much better than the kit lens)
Mid zooms
Sigma 24-70mm 2.8 EX DG
Canon 28-105mm 3.5-4.5 USM
Sigma 18-125mm 3.5-5.6 (if you need a big zoom and want a better lens than the Canon EFS 18-55mm kit lens)
Long zooms
Sigma 70-200mm 2.8 EX DG HSM
Sigma 100-300mm 4 EX DG HSM
Canon 70-200mm L USM (they are all overpriced like all canon L glass)