I've had good luck with Ameriglos. The bright orange front and black in the rear. I have this setup on all my Glocks. Not as pricey as Trijicons either.
I always try to buy them up when I see them. It seems like lately they have not gotten as much in as they used to. Oddly, only one of my four local Wal-Marts even carry them.
One in the chamber, always.
I always got a kick out of a sheriff's deputy I knew who said who wouldn't carry one in the chamber because of the "safety factor." He always said if needed, he could rack the slide at any time.
Thankfully, he changed careers.