I have a vogatek supergun that allows me to hook up and play PCBs through my TV/monitor. Also, I just use my existing DB-15 custom Neo-Geo joysticks with it.
That's pretty cool - I might have to look into something like that one of these days. There's a lot of great arcade games out there that I wouldn't mind getting my hands on.... MAME just doesn't quite do it for me.