After thinking about it for quite some time, I've come to the conclusion that the manual made for FACE's weirdo platformer, Hany on the Road, is, without question, among the best ever produced for the PC Engine.
That's due in large part to the game's awesomely colorful, clay-figure-populated cover:
Thankfully, those same clay figures (or at least I think they're clay figures) appear throughout Hany on the Road's manual, as is evident from the very first pages (such as the ones below).
Another thing I'm thankful for when it comes to Hany on the Road's instruction manual: It features (in the lower-right corner of the following page) a modeled-out-of-clay 10-ton weight. OK, so the crying dragon--also made out of clay, of course--is kind of cool, too.
The designers at FACE resorted to good ol' drawing when they whipped up the next two pages, interestingly enough. Normally I'd wish they had stuck with their clay models, but I'm refraining from doing that here because the illustrations below are pretty top-drawer (in my opinion, as always).
I'd like to note, by the way, that the little orange-haired dude who's riding a pink cloud and producing lightning bolts with his fingers is my favorite character in the game.
Anyway, enough about that. Hany on the Road's manual ends on a somewhat ho-hum note, as I'm sure you saw when you scanned the pages above--which seem to showcase the game's many items (including the aforementioned 10-ton weight).
See also: Previous 'Manual Stimulation' posts