H2 is good.
seriously, best love polyhedron ever.
H2 is the worst Adachi's manga in my opinion.
any reasoning behind that?
Nothing, it just felt artificial and forced, I couldn't feel for any of these characters.
However I loved Touch.
Complete opposite of how I felt, liked H2 a lot more.
My least favorite Adachi was probably the feudal japan one (can't remember the name).
Niji Iro Togarashi.
Yeah this one was pretty convulted, I couldn't get into it too.
Also for his recent one, Cross Game is pretty good
His style doesn't work too well outside the sports/romance genre. Katsu, H2, and Slow Step were my favorites.