It's been adapted by dozens of composers, and its debated who originally composed it. See all the composers here:
http://en.wikipedia.org/wiki/Funeral_march
* Marche funèbre for piano written by Frédéric Chopin in 1837, which became the 3rd movement of his Piano Sonata No. 2 in B flat minor, op. 35 and the theme for his Marche funèbre in C minor, Op. 72 No. 2.
* Franz Liszt's Marche funèbre, En mémoire de Maximilian I, Empereur du Mexique ("Funeral march, In memory of Maximilian I, Emperor of Mexico") from Années de Pèlerinage
* The Dead March from Saul by George Frideric Handel
* The Funeral March in Memory of Rikard Nordraak by Edvard Grieg
* The second movement of Ludwig van Beethoven's Symphony No. 3 (Eroica)
* The third movement of Beethoven's Piano Sonata No. 12 (written in the key of A-flat minor with a middle section in A-flat major).
* A funeral march, formerly attributed to Beethoven (WoO Anhang 13), believed to be by Johann Heinrich Walch, played at the Remembrance Day Cenotaph Service
* The "Funeral March" from the incidental music for A Midsummer Night's Dream by Felix Mendelssohn
* The Funeral March for the Final Scene of Hamlet by Hector Berlioz
* The Marche funèbre second movement of Charles-Valentin Alkan's Symphony for solo piano, Op. 39 No. 5
* Siegfried's Funeral March from Götterdämmerung by Richard Wagner
* The fourth movement of Alexander Scriabin's Piano Sonata No. 1
* The Trauermarsch opening movement of Mahler's Symphony No. 5.
* The song "Der Tamboursg'sell" from Des Knaben Wunderhorn, by Gustav Mahler
* The ninth variation from Benjamin Britten's Variations on a Theme of Frank Bridge, Op. 10
* The third movement of Mahler's first symphony, based on the children's song Frère Jacques.
* The 2nd movement of Brahms' Deutsches Requiem has the characteristics of a Funeral March but is in a slow triple metre.
* The "Funeral March": Adagio Molto from Shostakovich's String Quartet No. 15
* The Trauermarsch written by Anton Diabelli in memory of Michael Haydn for solo classical guitar.
* The "Funeral Music" for Akhnaten's father in Act I of the opera Akhnaten, by Philip Glass.
* The funeral march for Lìu in the opera Turandot, by Giacomo Puccini
* A funeral march for Napoleon Bonaparte, in Háry János, by Zoltán Kodály (after Napoleon has been defeated by the hero Háry János)
* The funeral march from Fibich's opera "The Bride of Messina"
* The funeral march during Tybalt's death in Prokofiev's opera Romeo and Juliet
* The funeral march in Ferdinand David's Concertino for Trombone and Orchestra