I'd happily subscribe to John's list and add some more arch-romantic suggestions of my own (in no particular order):
Heinrich Hofmann's Frithjof Symphony
Julius Rietz's Symphony No.3 (but Nos.1&2 would be nice too)
Julius Otto Grimm's Symphony
Emil Hartmann's symphonies
Alfred Hill's unrecorded symphonies
Hugo Ulrich's Symphonie Triomphale
August Klughardt's symphonies
Bronsart's symphonies (if they were ever found)
Jean Louis Nicodé's Gloria! Symphony
Schnyder van Wartensee's unrecorded symphonies
Frederick Cowen's unrecorded symphonies
Frederic Cliffe's Symphony No.2
Zygmunt Noskowski's three symphonies
Zygmunt Stojowski's Symphony
Philip Scharwenka's symphonies
und so weiter...
p.s. Alan and I obviously drink at the same well
Heinrich Hofmann's Frithjof Symphony
Julius Rietz's Symphony No.3 (but Nos.1&2 would be nice too)
Julius Otto Grimm's Symphony
Emil Hartmann's symphonies
Alfred Hill's unrecorded symphonies
Hugo Ulrich's Symphonie Triomphale
August Klughardt's symphonies
Bronsart's symphonies (if they were ever found)
Jean Louis Nicodé's Gloria! Symphony
Schnyder van Wartensee's unrecorded symphonies
Frederick Cowen's unrecorded symphonies
Frederic Cliffe's Symphony No.2
Zygmunt Noskowski's three symphonies
Zygmunt Stojowski's Symphony
Philip Scharwenka's symphonies
und so weiter...
p.s. Alan and I obviously drink at the same well