Canon Zoom Wide Angle-Telephoto EF 24-70mm f/2.8L USM Autofocus Lens

I use this lens a lot. If I leave with only 1 lens, this one is usually it. It's tack sharp and what you would expect from Canon's L-Series Lenses. It's great for videos and stills.

The only thing that bummed me out was a short time after I purchased it, they announced the series II version. If they added Image Stabilization I would have considered it. Without it, it's not enough of an upgrade for the money.

The Series II version is also a lot more expensive. If you're on a budget, I would not hesitate picking one up on ebay used.