Did you ever use a lens, expect little to nothing, and get a lot?
I know I've posted about this before, but I just took a casual shot of my tomato plants (hi Ned) with my MC Auto-Chinon 135/2.8 and was extremely impressed with what came out of the camera. I got this lens in a package with two other lenses and an ME body for basically nothing. I thought if it was crap, which I suspected it was, I would sell it.
Now, after seeing what this is capable of, this is going to be a lens I take with me to the grave. The colors are great and it's super sharp. From its humble looks and price, this lens just has no business being this good -- and it's extremely useful as a 200/2.8 equivalent on digital. The only problem is it has a bit of purple fringing, but that's OK.
Pretty sweet colors and tones, right out of the camera (no PP except pretty heavy cropping + web sharpening)
100% crop, f/4
So: what are your biggest surprises -- lenses that shouldn't be as good as they are?