I like the TruGlo tritium/fiber optic sights, or the Trijicon HD tritium sights with the bright orange front sight. I think both run around the $100 range.
Though you may run into problems getting them installed on your gun. The XD's factory sights are often installed with over 10,000 lbs. of pressure. Getting them out without damaging the slide can be almost impossible. Many gunsmiths won't touch XD sights for that reason. I've heard of some gunsmiths who have designed hydraulic sight pushers for XDs, but you might have to send your gun in to Springfield (I think they won't let you send just the slide; they're probably going to want to test-fire it after installing the new sights).
0331: "Accuracy by volume."