Tis the Sigma f/3.5.  I've stopped really considering canon lenses until i need the L glass (when/if i go full frame probably) - I've had a good run with sigma lenses.

"In every colour, there's the light.
In every stone sleeps a crystal.
Remember the Shaman, when he used to say:
Man is the dream of the Dolphin"

Rich Meadows Photography