Good point about the cosplay thing, though to be fair, I wonder how much of that has to do with the fact that it's not quite as easy to make a convincing Na'vi cosplay. Not only would prosthetics be needed, but lots of blue paint and a bodysuit, which doesn't always look good, and even then, the proportions are off. Not that people haven't pulled off harder cosplays, but still. I guess it is kinda telling that nobody goes to, or really remembers, the human characters in those films, other than maybe Quaritch, and they immediately turned him into a Na'vi too.
Fifth Element is a not-so-guilty pleasure. It's a bonkers movie, almost a live-action anime in some parts, and unabashedly European, even to a fault. I'd say Chris Tucker's character is one of the better instances of a sidekick being so annoying that he doubles back around again to being fun. But it works for the character- he's a larger than life radio host, and he's such a jarring opposite from how grounded and dour many of the other characters are that it works. He's in just enough of the movie that it doesn't make me hate it. Same with Gary Oldman; it's just a ridiculous part, but I think the reason it works at all is because of Oldman- anyone else in that role and it could easily have been such a nothing villain. But because of him, I always forget that he and Corbin don't ever actually interact in the movie.
I'm afraid I'll have to pull out the old "Pardon me, good sir?!" on the Peter Jackson slander as well. As others have stated, the Hobbit movies were basically a hostage situation with the poor guy. I don't think it was so much nobody was telling him no, it was that he wasn't able to tell the studio no. Those movies aged the poor guy more than the LOTR movies did, I think you could argue. But what isn't an argument is that the LOTR movies wouldn't be anywhere near as well done as they are without the dedication of Peter, Fran, and Philippa, who were passionate enough to know not only what worked, but what could be done without. The poor guy was done such a disservice on those Hobbit movies. I'd have loved to have seen Del Toro's take on it, though I do fear that, whether they turned out well or not, it would've brought him away from the more artsy fare that he does so well.