Worst Movies Ever!

Okay, so whenever I go off about a movie that I think is really bad, I inevitably end up offending someone because they liked the movie I hated. So, that said, this is all obviously just my opinion and meant for fun.
That said, I saw Vantage Point this past week. I am not going to say that it was the worst movie ever made, but I do think it is somewhere in the conversation. It was so, so bad, and so, so boring. The concept was that you got parts of the story from different people's vantage point. The concept was not bad, but, man, the movie sure was. I was falling asleep. There was this car chase at the end that lasted like half the movie (the whole movie was only about 80 minutes). The car chase was just laughable. Wow, the whole thing was really, really bad. Sometimes you just wonder how movies this bad are made.
I think bad movies are made even worse when they have famous actors or directors. It is one thing for a no-name director to get together a bunch of his buddies and make a bad movie. It is another thing for a movie with a budget to be a total bomb.
So, I would like to list off the four worst movies that I have ever seen. I would do five, but I didn't want to compromise the badness of these movies, just to make it a round number.
Number 4: Poseidon. This movie came out a couple summers ago and Karina and I went to see it. You know that it is not a good sign when you laugh at a lot of parts that are not meant to be funny. This movie was so bad. Kurt Russell and Josh Lucas. Terrible. Terrible. It is a perfect candidate for Mystery Science Theater 3000, where those three guys sat in front of the screen and mocked the movie while it was happening.
Number 3: Waterworld. I know that I am not the first person to talk about how bad this movie was. At the time of its release, it was the most expensive movie ever made. That made its badness that much worse. There is just nothing fun at all about watching this movie, and there is certainly nothing deep or meaningful about it. On that note, I think Kevin Costner is the worst famous actor of all time. And Field of Dreams is in my all-time top 10 favorites. Still, how this man got major movie parts eludes me. And he is especially bad when he has to have an accent. Watch 13 Days, and experience Costner's Boston accent. Classic.
Number 2: Celtic Pride. Fortunately, most of you will not have seen this one. But when I was in high school, my friend Zac and I went on a double date and this was the movie we saw. It was forever etched into our memories as the worst movie ever. It is about two Celtic fans who kidnap the star of a rival team. The movie is just not funny at all. It tries, and its stars try, to be funny, but it is just awful. I actually never thought that I would ever see a movie that I would rank lower than Celtic Pride. But about five years ago, Karina and I saw a movie that has to be the worst movie ever made. In fact, it makes the rest of these movies look amazingly watchable.
Number 1: Excalibur. How could a movie about King Arthur, the sword in the stone, Lancelot, and Camelot be this bad? Karina and I had been reading some Arthurian stuff, so we thought it would be fun to watch this movie. Man, it is so bad. I almost want to tell everyone to watch it, just so that you can experience how bad a movie can be. I don't even think that I could watch it again for laughs (I could certainly watch Poseidon again for laughs). If you ever want to teach your kids something about the Arthurian legend, don't make the same mistake we did. Stay as far away from this movie as possible.

There you go. As much as I disliked Transformers (and got a lot of flack for how much I ripped on it), it does not compare with how bad these four movies are.
Anyone have any nominations to round out the top 5?