RFCs (Request for Comments) are sometimes not very interesting (well..not for all) standards. Sometimes and not many, in fact. There are also very special ones, causing big laught. I have just found another one, so will share (current) list of my favourites.
No 1 is definitely RFC 1149: IP over Avian Carriers (often refered as ''IP by pigeon''). The document itself is short, what makes it great is implementation (esp. pictures).
My new number 2 is 1149 follow-up, RFC 2548: IP over Avian Carriers with Quality of Service. This time I don't know about implemantation. Text alone is still great.
Number 3 is about security. RFC 3514: The Security Flag in the IPv4 Header. The title is serious and looks boring. What's inside... I'll tell that this RFC has codename 'evil bit'.