My answer was not really tied to the appearance so much as the narrative of the Series Replay between Dale Wetzelberger and Arnold Blumberg with Don Greenwood's commentary. The play caught my imagination and I had to have the game.This question may need a complete do-over, because almost all of you are giving answers that are basically answering some sort of question about how the game's appearance was attractive to you. Most of these answers are of the "I liked the box" variety.
The moment I gave up SL and became an ASL fanatic was at Origins in 84 or 85. I was looking for the Squad Leader tourney and happened upon a motley group of fellows with a new game: ASL. They were holding a tourney and I asked about the new game and they enthusiastically told me it was much better than SL and asked if I wanted a demo.
I sat down to Ranger Stronghold with me as the Americans and Fish Conner as the Germans. It was a resounding defeat, but I still remember Fish telling me I did pretty good and he could see I knew how to play Squad Leader. ActionBurke, Mark Nixon and Eric Baker were all there watching the newbie get pounded. I vowed then and there to master this game.
To this day I am very happy that my first game of ASL was with my friend Fish.