What is your current favorite Roguelike? [Or all things roguelike]

While the first game got the wonderful esthetics going for it, I enjoyed all the sequels I played more. The 5th game for the DS was the best game in the series for me, and I suspect the Vita version Scott is currently enjoying surpasses it.
I think that Shiren 5 is a much better game than the original one, simply because when I played the original game again, it felt very simple and dated in comparison.