If you're interested in lenses at all, this video is worth a watch. While the high-volume output of the Canons and Zeisses out there is amazing, Cosina's F/0.95 25mm prime (sold under the Voigtlander brand) is a bit more old-school. Every piece is assembled by hand, manually cleaned and oiled, and tested individually for flaws. The result is one fantastic lens.
If I were buying a prime for a micro 4/3s camera, I'd seriously consider one of these. I mean really, owning a sub-F/1 lens has been a dream for years, and at around $1000 this is probably the most affordable out there (more affordable than a Leica Noctilux, at any rate). It's fully manual, too. And a 10-blade aperture! You better believe the blur is smooth.
You can skip the first part of the video, which explains depth of field, since you probably know what that is. The interesting part is the actual assembly.