The first Nosferatu film - Nosferatu, A Symphony of Horror - was released in 1922 by director F.W. Murnau and starring Max Schreck as Nosferatu. It is the original and IMDb lists it as #170 of their Top 200 Films of All Time (if you give such a list any creedence).
Then there's Nosferatu: Phantom of the Night - which was released in 1979 by director Werner Herzog and starring Klaus Kinski as Nosferatu.
Then there's Nosferatu a Venezia (German) which was released in 1988 by directors Augusto Caminito and Mario Caiano and starring, once again, Klaus Kinski as Nosferatu. Christopher Plummer and Donald Pleasance also appear in this film.
Then there's Embrace of the Vampire (AKA The Nosferatu Diaries: Embrace of the Vampire) which I adore thanks to Alyssa Milano's multiple nude scenes by director Anne Goursaud and starring Martin Kemp as the vampire (not Nosferatu, as he doesn't appear as a character in this film).
Then there's Nosferatu: The First Vampire which was released in 1998 (TV) by director Wayne Keeley. Basically, it's the 1922 film remastered, hosted by David Carradine, and features a soundtrack by Type-O-Negative. Supposedly hard to come by.
Then there's a mess of short and B-status takes on the franchise, such as Joe Nosferatu: Homeless Vampire.
Also, worth noting, is the 2008 release of the Bubba Ho-Tep prequel Bubba Nosferatu and the Curse of the She-Vampires. Can't wait.