.. and probably MOST movies is that the majority of them are bad. Bad to various degrees but REALLY bad more often than not.
Superhero movies are no exception.
Here off the top of my head are the best and the worst in terms of adapting the source material and just offering general entertainment. This includes ONLY feature films, there are a host of serials from the 30s and 40s that offer great comic book adaptions.
1. Batman (1966) A lot of hardcore Batman fans get upset by the goofier aspects of this fil starring Adam west, the truth is it's an accurate adaption of the comics for the 50s and 60s.
2. Dick Tracy (1991) Warren Beatty seemed like he had a lot of fun making this live action technicolor adaption of the famous comic strip detective and despite Madonna it's a good film with a crazy violent (in a crotons way) ending.
3. Flash Gordon (1980) Sam Jones is kind of a terrible actor but overall it's a fun romp through Mongo which hardens back to the days of Buster Crabbe playing Flash in the serials. Max Von Sydow as Ming the Merciless is brilliant.
4. Judge Dredd (1995) the first twenty minutes of this is spot on out of the comics, Stallone's wooden performance is perfect for the lawman of the future who's job it is to judge people. Sadly Stallone couldn't make a movie and keep his helmet on (in the comics Dredd never takes it off) but it still has elements of fun sadly missing for the recent Dredd film.
5. The Phantom (1996) Billy Zane puts on the purple suit and does a good job of it.
6. Spider-Man 2 (2005) Tobey McGuires sophomore effort as Spidey is nearly a perfect comic book movie. Accurate to the source and still fun.
7. Superman The Movie (1978) Christopher Reeve is great as a humble Superman, but there's just a bit too much camp and silliness to make this a great movie. Still, Gene Hackman is great as Lex Luthor and overall it's a lot of fun.
8. The Dark Knight (2005) Chris Nolan and Heath Ledger did a brilliant job on The Joker and you can't look away when he's on the screen. Sadly he's only in about half of it and Christian Bale, although give it his best, ruins his Batman performance with a voice that is just straight out ridiculous and incomprehensible.
9. The Avengers (2010) I wanted to like this, I really did. It's the number one movie ever made so a lot of you really did. Too much CGI and no sense of any real danger made it a snore rest for me. I'm sorry, too much smugness is not a good thing.
10. Superman II (1980) Filmed almost at the same time as the original, and made up mostly of cut scenes for that one put in with padding to make a movie. The idea is solid, villains that can actually stand up to Superman, the trouble is we were in a period where serious superhero movies were impossible and there's a whole bunch of nonsense mixed in as sub plots to make it just weak.
Hollywood will continue to churn em out and I'll likely keep on going to them, but I'm always hopeful someone will make a comic book movie that has some great story to it as well as fun and adventure.