I'm not sure how obscure is acceptable for an answer to this. Nielsen?
Rimsky-Korsakov? Berwald? Kallinikov? Those are just a few I wouldn't
want to be without.
Among the greats, don't forget Schumann! Oh, and Mendelssohn!
One might argue whether Mahler 1) was a Romantic composer and 2) wrote
nine, rather than ten or eleven, symphonies. The second question would
apply as well to Bruckner.