So in case you frauds posing as Mega Man fans missed it, the Zero series of GBA fame are being compiled onto a DS collection, releasing in Japan this April.
The Zero franchise not only features beautiful art unique among the franchise, but it also has the tightest gameplay and difficulty. The four titles also placed an incredible amount of emphasis on plot, story, and character development; and unlike some other Mega Man titles, these games pull it off without feeling ham-handed. This is genuinely good writing, and the series' focus on narrative makes it stand out among the other Mega Man games. They also have outstanding audio, and have perhaps the best and most rock-solid soundtracks in the series (every track is good, even if not spectacular).
In short, if you haven't played a Mega Man Zero title (but play them in order! there's story), you are a Mega Man poser. ^_^