A ghost, an eccentric theatre actor or a flamboyant genie, Amitabh Bachchan has done quite a few over-the-top roles and not delivered big hits in four years. But for filmmakers, the megastar is still a phenomenon they can't wait to sign on.

"I would love to cast him for all my films. I just hope that I keep getting ideas where I can fit him, " said R. Balakrishnan, director of his forthcoming film "Paa".

Relasing Dec 4, "Paa" features Amitabh as a progeria patient.

"Amitabh Bachchan has crossed that mark of a hit or a flop affecting him. He is a phenomenon. He is the first veteran where stories are written keeping him in mind. Whether or not a film works is besides the point. He is not competing with anyone here, " trade analyst Taran Adarsh told over phone from Mumbai.

"Every director wants to work with him at least once in his career. They've grown up watching him on the big screen. He is an encyclopaedia on acting. He has a different range altogether. He is a superb actor...and we can't deny that fact, no matter what the fate of a film, " he said.

Some of the 67-year-old thespian's films have turned out to be over-hyped in terms of both content and characters, with the recent one being "Aladin" that was declared a dud on the first day itself. Amitabh plays a flamboyant genie in the movie.

Even his special appearance in Rakeysh Omprakash Mehra's "Delhi-6" early this year, as Abhishek Bachchan's grandfather, could not save the film from sinking. But he still rules the desire list of filmmakers.

"He is in demand because he is Amitabh Bachchan. He is a cult (figure). He has worked very hard and given success after success earlier. After his comeback from a break a few years ago, he is now having fun with cinema, " said film critic Omar Qureshi.

"And he can afford to do that even if it means doing a crazy character in 'Ram Gopal Varma Ki Aag'. He is doing roles that he finds interesting. If the film doesn't work, that is not his fault."

And cinema too has undergone a sea change with time.

"Take his characters in 'Nishabd' and 'Aladin'. No one could dare do that earlier. He is just going with the flow. His performance cannot be doubted. He is too good as an actor, " explained Qureshi.

While Amitabh featured in duds like "Family", "Darna Zaroori Hai", "Kabhi Alvida Naa Kehna" and "Baabul" in 2006, a string of flops followed in 2007 too with "Eklavya: The Royal Guard", "Nishabd", "Jhoom Barabar Jhoom" and "Ram Gopal Varma Ki Aag". Two of his outings the same year - "Cheeni Kum" and "Shootout at Lokhandwala" - were critically acclaimed but were not money grossers.

Last year was again disappointing with commercial failures like "Bhoothnath", "Sarkar Raj", "God Tussi Great Ho" and "The Last Lear".

But writer-turned-director Rumy Jafry has no regrets for the failure of his film "God Tussi Great Ho" because it starred the Big B.

"It's a dream for every director to work with him. Despite his age, he still works as a student and is completely a director's actor. Neither does he interfere in anything. Look at 'Paa' for instance. He sat for close to five hours just for the make up and that shows his patience, " said Jafry, who cast the Big B as God Almighty in the movie.

Jafry can't stop praising the veteran's professionalism.

"The whole world knows that there is no bigger actor and star than Amitabh Bachchan. There is no star in the industry more disciplined than him. Even if he was 10 minutes late, he would make sure to inform, while there are actors who are over two hours late without any notice, " Jafry told.

But Bachchan prefers to be modest and says he is just a character artist nowadays.

"May be in the early years, they (audiences) came to watch my films because I was in it. But now I am just one of the credit titles. I am not that important, " Amitabh had told in a recent interview.

"I am a part of the crew and the cast. Even in my early years, I used to think that. I think the product itself is more important. It's the film that is going to make you or your name or give you visibility. If that goes wrong then everything goes wrong. So one must work as a team so that the product works, " he added.

The star is still on a signing spree and has four projects lined up - "Paa", "Teen Patti", "Rann" and "Johnny Mastana".