My go-to iron sights for carry guns - Trijicon Heavy Duty Night Sight Set, Front Outline, Springfield XD-S

These are my favorite style of iron sights and I have them on all my carry guns. The front orange dot is bright and super easy to pick up and visually sits right where it's supposed to: in the rounded notch in the rear sight. Having the ledge on the rear sight for one-handed slide manipulation is nice, too. The green tritium is also very easy to pick up in the dark. I had a gunsmith install these sights for me as Springfields have notoriously tight factory sights and I didn't want to put any dings/scratches on my pistol trying to install them myself. Totally worth it.