I'm not wildt, nor do I intend to speak for him, but there are an abundance of things that made DA one of the greatest games on this forum -- I personally think it's the best.
First off, we have the characters and artwork. Not only are the models incredibly designed and detailed, but they all also have their own unique stories and backgrounds: the tragic story of Stella, the damaged history of Mido, the redemption? arc of Christina, the hooker with a heart of gold trope come to life in Carli. The fact that these vignettes allow us to see the characters beyond images enhances the overall product, and the fact these vignettes are different from one another adds a certain shade of identity to each woman.
Secondly, the customization/paths element of the game was really important to me. Not only were we able to choose different approaches in our relationships (like the rougher, BDSM route with Mido versus the softer, almost love route with her), we also were able to change our petname in each relationship. You could have Judy call you Daddy, and then have Carli call you Lover -- different girl, different role. Again, this served to add another dimension of identity to each character, and the CG models transformed into legitimate characters. The fact that there are several paths in the game gives it replayability and ensures that there is at least something for each player. In addition to this, I also liked the text in the game. It's often difficult to write out dirty talk without it sounding embarrassing or silly, but I felt that DA was able to combine images with dirty talk almost seamlessly.
All these distinct factors allowed DA to rise above all others on this forum, and allow it to serve as a testament to what occurs when a developer pours an incredible amount of effort, dedication, heart, and skill into a project.