I have had this conversation often and i always say that game to movie adaptions will never be good,everyone who plays a game always gets something slightly different out of it so when its turned into a movie it never fits in with the subject version of how it should be in our heads. And whats more the games that get turned into movies are really only ever the commercially successful games that sold millions of copies and are only made as they are sure to make at least its budget back and then some as its already got an established audience even if we all go watch it just to see how they ruined yet another fondly remembered title.
As is why i will go and see the new the POP movie,I think as gamers we like to be right about these sort of things and will pay for a ticket even though we know it will disappoint just so we can then walk out and say "I told you so!" I think the best praise a game based movie can get is that if it was called something else or been a stand alone movie it would of been OK.
As for Movie based games i think they have a much easier task and can be good but the trend seems to be that the best of them are made years after the movie release as its pretty much a universal truth that any tie-ins around the release are nothing more then jumped up promotional material.