I think i will have to go for MI3, simply on the greatness of some of the scenes, like the vatican city one, however it would get nowhere near by top 20 films because of the sheer awfullnes of Tom Crusie's acting.
Alright, I just watched MI3 this last weekend and I must say it was good. Some part of the movie was funny and most of the action was shooting. It wasn't a great movie but it beats all the other ones out there right now.