I favour primes myself and on any canon DSLR the 50mm f/1.4 USM is a cracking little lens. The 85mm f/1.8 USM is also very nice. If you want to go up the range the new 85mm f/1.2 L USM II is jaw droppingly sharp. I've heard very good things about the 35mm f/1.4 L USM also though only taken a couple of shots with one so can't really comment with authority.

Where I make an exception and have zooms I really rate are the following zooms:

16-35mm f/2.8 L USM II is just amazing easily up their with primes for sharpness but also has a certain something about the image quality that's just beautiful.
24-70mm f/2.8 L USM is as sharp as a prime. In fact they test primes against it on the bench at Canon (a contact of mine stated). Certainly I use one probably more than my other lenses (I'm on 5D with no crop factor)
70-200mm f/2.8 L IS USM the image stabalizer gives 3 stops of hand holdability extra and it is as sharp as any prime. Again this is also a lens where the colour and contrast tell a story an MTF chart can't. A cracker of a lens! Also when used with 1.4x Tele II there is no significant image loss.

Back onto primes...

The 135mm f/2 L is possibly the sharpest thing I'd ever seen until the 85mm f/1.2 L II. It's a wonderful lens.