I like matte paper best for smaller prints to be viewed without glass over them. No glare is really nice!
Under glass the glare problem with gloss paper goes away, since what ever reflections the paper would be suffering from, the glass is much worse.
Richness- If you mean deepest, darkest blacks then glossy is where it is at.
I personally settled on semi-matte paper from Forte a long time ago and haven't run out yet. So I'll be looking for new paper soon.