I'm not surprised that CVRL has the most votes. It's the one that keeps me coming back even after all this time. In fact, all the recent games that I've developed have a class system that is inspired by the class system in CVRL (Underhall for example). That is, a small number of highly different classes with very different gameplay.
However, I want to point out that CVRL also has the best graphics. Even though this shouldn't contribute to it's success, I still wonder if it does. In my own games, I'm always torn between going for better graphics, or leaving them plain and simple. I'd like to think that players see beyond graphics, but the history of the video game industry kinda suggests a graphics "arms race" over time.
Maybe judging the success of an ascii game by comparing it to the success of a game with amazing 2d graphics makes the ascii game look less successful than it actually is.