My opinion, everyone else will have theirs
- Not a fan of Hollywood celebrity sigs on comic books. Fine on magazines but not comics. There are subjective exceptions and that comes based on my personal preference like Ferrigno or Campbell.
- Agree on different colored pen ink on multi sigs, although you may get lucky sometimes depending on the cover art and sig placement.
- Fading ink. I hate to be the 200th book signed from a single marker.
- Smudged sigs - I have a Herb Trimpe sig that was likely stacked on over while it was wet
- Artists that never had anything to do with the book. A subjective topic since you can make exceptions like Romita Sr or Stan Lee, so my opinion on it may change as artists eventually become "legends".
- Ugly remarques, lots of examples with Bagley. Some of them are just improperly placed doodles. I would prefer a proper sketch on a blank cover or a simple sig.
- Sigs on the inside pages, what's the point? Back cover may be acceptable but would rather have them in front.