I’m using a 60D and have been recommended 3 lenses
the Sigma APO 50-150mm, Tamron SP AF 17-50mm and Tokina 11-16mm, I’ve not actually had the funds to buy them all yet, but they are supposed to be great quality lenses and all have a constant f2.8 max aperture. I also have a couple of old Pentax K mount lenses which are very good and have a really smooth focus and zoom capability compared with even the canon pro lenses I have used.