I am the snottiest person about pens/markers, especially when it comes to signing books because it has to look absolutely perfect (espec. since I have a pen name and have to practice for an hour before I'm confident enough to sign a paper copy).
The absolute only thing I will ever use is the Tul brand pens I have fallen in love with. I like the gel over the ballpoint, but it writes super smoothly with really crisp lines and that's important to me, and the pens come in several variations of thickness (I like the fine point for signing, extra fine point when writing).
But if you don't like gel/ballpoints pens I have nothing xD