Teenage Mutant Ninja Turtles: Turtles Forever
This feature length cartoon, created in celebration of the TMNT's 25th anniversary, premiered at last year's San Diego Comic Con, and has dealt with many disputes. It's currently not even on DVD, but the entire movie is here!
This animated gem brings together Ninja Turtle fans of all generations, it has the 1987 cast, as well as the 2003 cast working together to take down multiple Shredder's. Enjoy!
Part II, Part III, Part IV, Part V, Part VI, Part VII, Part VIII, Part IX, Part X