One of the very nicest features of AyA guns (which I wrote about a month ago, here), were the safety buttons. I liked them so much I took a picture of one. As you can see, they stick up high where you can't miss them and they practically grab your thumb like Velcro thanks to the sharp hand checkering on top. They snick off easily with a mere flick and are easily among the most positive safeties to operate that I have ever tried.
That brings me to the subject of safeties good and bad: a good safety comes off easily so you don't even have to ... ... think about it as you raise the gun to shoot.
Personally, I dislike the safety on the Benelli Nova most of all. It is tiny and difficult to find in its spot in front of the trigger guard. For repeaters, the Browning Gold's big, triangular, easy to push safety is the all-time best.
When it comes to O/Us, I have seen more bird's lives saved by the Browning Citori/Winchester 101 style selective safeties than by any other. These safeties slide side to side to select the top or bottom barrel, and forward to make the gun ready to fire. What happens instead is, in the field when people try to push them forward, the safety slides halfway between "O" and "U" and won't go forward at all.
The gun stays on "safe" and the bird flies away not only unscathed but unshot-at.
Here is a simple trick to solve that problem forever: if you are right handed, switch the safety over to the left to shoot the top barrel first and leave it there. If you're left handed, leave the safety pushed over to the right,always. There is no room to explain (and a good magician never reveals his tricks anyway) but I promise that works.
Meanwhile, the subject is safeties: favorites, least favorites, funny stories, horror stories, whatever you got.