I'm only about half into Touhou apart from the camera ones, which are genius (and, yes, only tenuously shooters - I don't care). As far as pretend arcade games go, Zen-Ichi ([link=http://www.youtube.com/watch?v=HSykExeZDy8">train stage! why is there always a train stage?) is fabulous. Kind of old and import only, so you might end up needing to resort to piracy to find it. I also quite like
Nice. The Shanghai Alice shooters are a league of their own. I actually forgot they were doujin. I've already got most of them . 16bit are almost unplayable for me these days.