Another fan of XKCD :) Discovered it through the "new" What if section - and has then proceeded to the beginning of the XKCD comic. And found that I needed this page to fully understand and appreciate many of the comics.
I have so far (May 2014) only progressed through the first 400 comics (+ references) but have read all the new since October 2013. So there may be many favorites waiting for me. (Reached no. 400 on May 28th 2014, then 480 September 15th 2014 - slow progress at the moment. 500 in November. 530 reached in January 2015.)
This is just a list of some comics I really appreciate: