Ok well...I don't have an Canon SLR, but I do have a Canon S5 IS...which can shoot in full manual as well as has adapter lenses capabilities , I guess what I was wondering is if there was anyone in the group that might be able to tell me what the most commonly used lenses were for Canon...or that you felt was most useful?
I shoot mostly nature photography as well as animals in motion, therefore I like to have a lot of range in my lenses. The one lens in my collection that is on my camera more than anything else & has allowed me to capture some amazing images is not actually a Canon lens. It's a Vivitar Series1 28-300mm AF Zoom Lens for the Canon. I love the range it gives me for subjects in motion. It does require some light...even more so with the UV filter I've got on it. But it still remains quite versatile & sharp...love it!
(I probably should also add that I originally bought this lens for my Canon film SLR...so it actually becomes a more powerful beast on my 20D.)
EVERYDAY LENS
Although I am new to photography, I did months of research and concluded for my 1.6 crop camera I needed a 17-55mm IS f2.8 lens for my everyday use. The short end is good for landscapes and the long end is good for portraits. It is the equivalent to a 24-70mm on a full frame camera. The sharpness is its best feature (a majority of tests I reviewed show it is sharper than the 24-70mm). I have a high rate of keepers because of the Image Stabilizer. It is pricey but the lens is mostly where the quality from a photo comes from. The color is good, but I have seen better. The main downside is that it is EF-S and if I upgrade to a full frame camera I have to sell it and get the 24-70mm.
PORTRAIT
The long end of the 17-55mm is fine for portraits on a 1.6 crop camera, but my 85mm f2.8 has much smoother bokeh. This seems to be the best range for portraits for me. I may get a 70-200mm f2.8 someday, but when taking portraits I have time to walk the desired distance from my model. This lens has replaced my 50mm f1.8 (which is sharp but has auto-focus issues) as my favorite portrait lens.
For portrait work, yes a 50mm and 85mm are the popular focal lengths. At least the f1.4 in 50mm, f1.2 if the budget allows. Sigma just released a 50mm 1.4 that is getting great reviews. The Canon 85mm 1.8 is capable of amazing photos. Again if money is no object, the 85mm 1.2L is supposed to be one of the best portrait lenses out there. But the 1.8 is no slouch and makes the price difference of the 1.2 hard to justify.
Since it appears you do location work, a good ultra wide angle should be considered. Sigma 10-20mm and the Canon 10-22mm are great on crop bodies. Sigma 12-24 and the Canon 16-35 are great on the 5D. UWA will allow a whole new way of looking at how you compose your shots.
www.pixelpeeper.com is an excellent resource for looking at images from every lens out.
Also you may want to consider the Sigma 30mm f1.4, Canon 35mm f3, or Canon 35mm 1.4L on a crop body. I found myself using the 30mm 99% of the time over 50mm. So I sold my 50mm and got a 1.4 TC.