I don't know that it's the "best" but I thoroughly enjoyed Wild Hogs.  I laughed 'til it hurt.

i have lots of favourite movies but i think homeward bound would have to be the best. every time shadow comes up that hill near the end the tears are rolling down my face. love animal movies and kids movies like toy story, lion king etc. it's good to have a laugh and a good cry. and when i have a good cry hubby has a good laugh at me.  

Like a few of the others where to start?  With the oldies godfather, casablanca and it's a wonderful life( no I am not that old!!)  More recently POTC 1,  most of the pixar ones, the bourne trilogy.