It's been a while, so here's a new one.
Which boss has the best nonspells?
The two that come to mind are (boss) Sakuya and Kaguya. Sakuya's first two and Kaguya's first in particular require a lot of quick dodging and "reading ahead" skills which makes them really fast-paced and fun, and somewhat VoWG-ish in style. Sakuya's last has annoying hitboxes, but tests your reading skills and is satisfying to dodge as well. Kaguya's last also has a lot of reading, but in a different way, and it manages to be pretty intense despite being slow and not too hard. Her second also has great random dodging with some strategic misdirection, although her third isn't that special I suppose.
There's also a few others that I like, such as Mokou's 6th and 7th (and probably Ran/Yukari's 7th as well, but I usually chicken out on that one and use a border), which are challenging, but always fair and require quick switches between reading the fast and slow bullets. Sanae's (boss) first is similar to Sakuya's and Kaguya's first, although it has a tendency to wall you if you're fooling around.
Yes, I'm a fan of reading-based random dodging. :derp: