Check out what a fan put together back in June -- A World War Hulk trailer featuring footage from the various Marvel movies.
Seems about a good time as any to check it out as Marvel Studios president and producer Kevin Feige recently mentioned Planet Hulk and World War Hulk.
As of right now there doesn't seem to be any plans in place for another Hulk movie with the reason cited being that Hulk works best as a supporting character.
Would a Planet Hulk movie work?
A few benefits Planet Hulk has is that it is featured on another planet, features a weakened hulk and one more relatable.
A World War Hulk movie would be a slightly different story as none of the X-Men and Fantastic Four would appear. It basically would be Avengers vs. The Hulk, not that the Assemblers taking on the Indestructible one would be bad by any means.
Movie footage included is taken from:
X2: X-Men United (2003)
Fantastic Four (2005)
X-Men: The Last Stand (2006)
Fantastic Four: Rise of the Silver Surfer (2007)
The Incredible Hulk (2008)
Iron Man (2008)
X-Men Origins: Wolverine (2009)
Transformers: Revenge of the Fallen (2009)
Iron Man 2 (2010)
Captain America: The First Avenger (2011)
Transformers: Dark of the Moon (2011)
The Avengers (2012)