So far I read:
Heart of Thomas
Natsu e no Tobira
ZANKOKU NA KAMI GA SHIHAI SURU(reading)
kaze to ki no uta
From Eroica with Love
A, A'

Patalliro! is a very funny gag manga with a shounen-ai subplot, also an anime
November Gymnasium, a sort-of alternate telling of Heart of Thomas. It was published first, but only because HAGIO Moto felt that she wouldn't get to write Heart of Thomas, which was the original idea.
Poe no Ichizoku
Hi Izuru Tokoro no Tenshi - not much is scanlated, but it's in process
Earthian
Banana Fish is often mentioned with these titles, but it's only listed as shoujo