This is my wonderful Christmas present from my super-wife, Marline. It's a Sigma 18-125mm f/3.5-5.6 DC zoom lens, which will replace two of my current lenses.
See my shots taken with this lens.
UPDATE: I'm pretty sure Sigma has discontinued this model, but here's my take: It's soft on the wide end (which is why I got the 10-20mm!), but great from about 40mm to 125mm. It has an amazingly close focusing distance when fully zoomed (just over a foot away), which can yield some neat shots. It's noisy when focusing, but that doesn't bother me, as long as it's fast.