[KegCommando]

Looking to add some and wanted to know what people preferred.

Thanks.

[HoosierQ]

I will be interested in what responses you get. I have a 590 with a brass bead. My buddy has a 500 with the fiber optic, red and green, ghost ring. Wonderful sight picture and fast to acquire...good in low light.

He bought the gun as it was and didn't know much about the sights.

[Fumbler]

The Mossberg factory ghost ring sights work fine for me.
They're the cheapest too.
They're not super accurate, but I can hit 10" steel plates at 100 yards with slugs almost every time.

The only thing about those is you have to solder (high temp silver solder) the front sight onto the barrel yourself or have a gunsmith do it. That involves removing some of the finish.
If you plan on refinishing the gun then that's not really a problem. If you're careful when soldering then you could probably get away with just cold bluing the exposed steel.

Here's a pic of mine:
http://www.thewolfweb.com/photos/00495337.jpg

[KegCommando]

The fibers sound interesting.

Fumbler - Nice digital job there.

[swampboy]

For the price, the factory set is hard to beat. Here's what I did. Bought a synthetic 500 (factory drilled for GR sight) with 28" VR barrel off of Gunbroker for $125 + shipping/transfer. Bought a 18.5" barrel with front sight installed & rear GR set from Mossberg, all for about $125. Now I have the GR setup and an extra barrel and didn't have to do any gunsmithing (drilling, soldering, etc).