So, in Germany they have a channel called 13th Street that's owned by the NBCUniversal Conglomerate, and according to their literature they are well known for their crime and horror offerings. A German design firm designed some award winning stationary for them addressing everything from stapled documents to optical disc holders. Going off the horror angle rather than the crime angle that 13th Street currently favors they created a series of zombie heads in various states of destruction. My favorite is the two hole punched paper. When viewed as an individual piece of paper there are holes in the zombies heads, but when placed in a binder the zombie heads are now pierced. The official description is: "Invoice: When filing this sheet the zombie-heads get skewered."
They also have an envelop which they describe as: "Envelope: Ripping the envelope open tears out the zombie's eyes." You can click through to see all of the blood and gore if you so desire. While this kind of creativity can go a long way toward keeping the young people in your office interested in filing paper work and can get your company some good press, most people prefer the a more professional approach for their businesses. Just about anybody could be happy with standard white envelopes or if you want to be really fancy you can grab self adhesive envelopes with windows. The whole forced ripping open of the envelopes only requires more effort as you'll have to track down some envelopes with tear strips that are affordable.
Equally interesting to me as the zombie stationary is the two-hole punched paper. You can find tons of two-hole paper punches or tons of three-hole punched paper, but I couldn't track down any paper with just two-holes that looked like the zombie stationary. I found a five-hole punched paper that looks to be compatible with the paper in the above picture, but they all seem to think anything different than three holes and you are working for a hospital or law office. I couldn't even find a good two ring binder anywhere. They seem to be readily available if you live in Europe or Australia, but in the good old United States of America we've done an excellent job of standardizing ourselves to paper with three holes and binders with three holes.