The present article lists both symphonies that are numbered and have an additional nickname as well as symphonies that are known exclusively by their name or key.
Symphony No. 40 - Great G minor, or simply The Fortieth as the number started to work as a nickname, making the mentioning of it being actually a symphony redundant.
Symphony No. 8 - Unfinished (occasionally listed as No. 7)
Symphony No. 9 - Great C major (usually appears as No. 9 in modern editions [this numbering was based on the supposition that the Gmunden-Gastein symphony had been lost; it has now been established that the Great C major is in fact that work], older references may list the work as No.7 or rarely as No.8 [Neue Schubert-Ausgabe])
Symphony No. 10 - The Last (reconstruction based on sketches)