Many of us want the very best, but we often compromise with what we can afford. But if the money is no object, what would you get? For me, they are.... Ultra Wide (landscape photography) In my opinion, the best overall ultra wide lens is EF 14mm f/2.8L II USM. Fantastic performance with comparatively mild distortion. Great for both indoor and outdoor landscape/architecture photography. Wide-Angle Prime (full-body portraits and group shots) There is no better wide-angle prime than EF 24mm f/1.4L II USM. Although I personally prefer longer 35mm focal length of EF 35mm f/1.4L USM, the lens is showing some age (e.g., no circular aperture blades, no weather sealing, slower auto focus, older optical elements). Standard Zoom (walkaround lens) L snobs can cry foul all they want. That won't change the fact that EF-S 17-55mm f/2.8 IS USM is the best standard zoom on the market. Top-notch performance, 3-stop image stabilizer, fast, and surprisingly good build quality (although a notch below that of L-series, and without weather sealing). For those with a full-frame body, I would badge the honor to EF 24-105mm f/4L IS USM. Portrait Prime EF 85mm f/1.2L II USM is the finest portrait lens on the market. Telephoto Zoom EF 70-200mm f/4L IS USM may be the best zoom lens Canon has ever made. Sure, if you need the extra stop, f/2.8 is your obvious choice. But from f/4L and on, this lens kicks some serious stuff, optical performance at or near the best of prime lenses. Telephoto Prime I think the nature of telephoto prime photography requires multiple lenses, depending on focal length requirement. EF 135mm f/2L USM is perhaps the best starting point, going up to EF 300mm f/2.8L IS USM then all the way to EF 800mm f/5.6L IS USM. Macro The current king of macro is EF 180mm f/3.5L Macro USM. New EF 100mm f/2.8L Macro IS USM remains to be seen and very well likely take the crown, although some will want 180mm focal length still. Tilt-Shift TS-E 17mm f/4L or TS-E 24mm f/3.5L II, depending on focal length requirement.