The 30 Days of Marvel meme:
Day #13: Your least favourite character.
Moon Knight.
Really: this hero had the lamest and least original origin story ever. Every single story I have read in which he makes an appearance has been a boring one. In his civilian identity - or identities - each persona is less interesting than the next.
I can't think of anything redemptive here. Thank goodness he isn't on any of the teams I care about.
This being said, I do believe there is no character ever conceived who can't be made interesting with a good writer and a good story. Take the Scorpion, once a rather low-powered Spider-Man villain. After a few transformations, he was most entertaining as Venom in the Dark Avengers stories.
So maybe Moon Knight could be made interesting, but it would take a gargantuan effort. The really good writers are smart enough not to touch him.