For those who read and replied to my "Should I go FF?" thread: I decided to stick to the Canon T3i for the time being and focus on practicing (I'm quite the newbie still), improving my photography itself, and spend my money on better lenses, rather than upgrading the body to FF (or even to a better crop frame body). With that in mind, I currently have the kit 18-55 EF-S lens, and a couple of excellent prime lenses (28mm f1.8 and 50mm f1.4). The primes are great, but not the most versatile for a "carrying around" lens. The kit lens has served me well and continues to do so. But I'm considering upgrading in that department (meaning, a versatile lens that would be on the camera 90% of the time). I've read some (including opinions here) on the following lenses: EF-S 17-55 f/2.8 USM EF-S 17-85 f/4-5.6 USM EF-S 15-85 f/3.5-5.6 USM EF 17-40 f/4L USM I like taking photos of landscapes, but that is not exclusive. I also like having something versatile for things like : Street photography, Backyard photography (birds, pool, dog, plants and bugs) and some portraiture (but not much). I have also considered trying out macro (never tried it before), in which case I have read great things about the Canon EF 100 f/2.8 USM. I am fully aware of the crop sensor vs. FF (ie EF-S vs. EF) dilemma. I have considered upgrading to FF down the road, but am also content, I think, for the time being (and even possibly for the long run) to sticking with the crop format. And I feel I can always resell my EF-S lenses if I ever upgrade to FF. I say this so as to avoid the advice of "don't bother with EF-S lenses" that is bound to be given me here With that variable out of the equation, I'm interested in your thoughts on the various lenses listed above, purely in terms of versatility, image quality, and general ease of use (weight, etc.) They're all priced in the same general ballpark (ie under $1000 USD), as I am not keen on spending astronomical sums on the more professional lenses. So, thoughts and comments?