I figured I'd start by sharing a photo of my 590. It's been treated rough in the field but always cleaned up when we get back home and has served me well.
I've pretty much run it stock until recently, but for it's 20th birthday I figured I'd dress it up some
Specs:
Mossberg 590 20" bbl bead sight
NOS wood furniture from Numrich
Brownells extended steel safety
CMD MTR mount
Streamlight TLR-1S
HSGI velcro shell caddy
Blackhawk sling and Talon swivels
Remington 00 buck managed recoil patterns great and is a comfortable load to shoot so that's what I usually feed it.