Pretty Self Explanatory. Mine is The Shawshank Redemption

Avatar.

Its a 5 way tie between Casablanca, The Princess & The Frog, Up, Wall-e and Speed Racer

Edit: How could I forget Speed Racer

I'm not sure whether you're asking for two different movies or one. I wouldn't really consider my favorite movie the best movie of all time. I would reserve that for a film that really did something special for films overall and is historically important. Maybe something like Citizen Kane, Casablanca, Dr. Strangelove, Annie Hall, Raging Bull, etc. Overall, Citizen Kane is considered by most to be the greatest film of all time.

My favorite movie is Ghostbusters. 

I was afraid of someone saying that. Have you ever heard of Dances with Wolves? Exact same plot minus blue aliens.

No I haven't but I like the sound of the title.

Avatar is NOT my favorite movie of all time, but that is a very flawed analysis of the two movies.  However, let's not start yet another discussion on the same topic here.

OT: If we're mixing favorite with best, either Pulp Fiction or Miller's Crossing.  My favorite movie of all time is probably O Brother Where Art Thou.

My Favorite: Pulp Fiction
The Best.. now that's harder to say, if I had to throw something out there though I'd probably say A Clockwork Orange.

The best movie of all time, and my favorite?

The Godfather, and The Godfather.

I will only talk about my favourites not animated movies:

1.- Legally Blonde
2.- Miss Congeniality
3.- I can't think of one right now