I have a friend like you. He loves everything he sees, he has no discriminating taste. He's automatically gives a film a 9/10 because the theater got the image so big onto the white screen or when the video/audio are in sync.
There's a lot of crap that I've watched, but was "entertained" by it. To me, "entertainment" value doesn't always equal quality. I'm entertained by the sheer stupidity of films like "Mac and Me" and "The Room," but neither of which will ever be described as good. I'm really not an elitist, I hate most of the Oscar contenders each year and find them incredibly stuffy and boring. A good film is both intelligently produced and constructed as well as being on some level entertaining.
Favorite movie of all time? Clue: The Movie. Vastly underrated and under-seen by the general public, but it has a stellar cast, clever dialogue, and an intriguing murder mystery.
As for a top 5, I don't usually limit myself to such a list. But I'd have to say that Clue, Zodiac, and the Back to the Future trilogy as a whole are among them. I usually go by movies that I can watch over and over again, always find something new, and always be entertained on each viewing. And I believe all three are smarter than the average film, there are multiple levels and layers to them. A lot of films lack that aspect nowadays.
Your top five?