Wow, you guys are making me wish I had been aware of the DK community in 2007.
Back when I first discovered DK, a few local bars had arcade machines, so I played several times each week for about 18 months, between 1983 and 1985. After achieving a personal high score that I was happy with, I stopped playing and turned my attention to other interests. At some point during 2005-2007, after having not touched the game in 20 years, I searched for a free online version to play; I don't recall what prompted me to do so. It involved a bit of trial and error, but I was able to find a website that hosted the game and seemed to emulate it accurately. I played occasionally, competing only against myself, trying to top my personal best from the arcade days. I had no idea there was a killscreen or a world record, or that anyone might be actively pursuing either one.
It wasn't until the spring of 2010 that I somehow stumbled upon "The King of Kong", Twin Galaxies, MAME, etc.
Better late than never.