[Rover]

Canon 16-35/4 L IS (I do sound like a stuck record BOTH recommending that lens AND saying that I sound like a stuck record on this - a nice recursion there). It weighs 615 grams, accepts moderately large filters and optically is nigh on flawless. You won't find any better option, especially with the weight and size being a notable consideration.

 

You can go totally left field with the Sigma 12-24 however, especially if you own a 24-xx lens.