I can say definitively, this should be your 1st “L” lens. I bought mine nearly 9 years ago and still use it nearly every single time I shoot.
This is what I believe is the perfect general use lens for shooting weddings, portraits & Video with dSLR Cameras. I believe you can cover an entire wedding with the 24-70 2.8.
There are many out there who will argue that the Canon 24-105mm f4 is a better all purpose “L” lens because it has Image Stabilization and a wider focal length, to which I answer: that extra stop is HUGE (think about it, the 24-70 will let in twice the amount of light as the 24-105 when shooting wide open).
There are others who will say the Canon 17-55 2.8 Canon 17-55mm f2.8 is a better choice for those shooting with 1.6x Crop Sensors, because the equivalent focal length would be closer to “24-70”. This is true, however, I still say stick with the 24-70 2.8, because it works GREAT on both 1.6x and Full Frame Cameras. EF-S Lenses like the 17-55 won’t work on a Full Frame camera, and if you ever upgrade, you wouldn’t be able to use it.
The 24-70 2.8 L is about to be upgraded (long awaited) to a version II lens. This should occur later this fall and I will update this page as soon as I have it in my hands. Until then, take it from a maven, this is the first “L” lens you will want to purchase.