I just got Irish Luck last year, so not really sure what it's like...
Here's a few that I have ...
Pitch Black (I'm not sure how big this one gets)
Puddles and Bumps
Lily Pad (just emerging) Not dark in color, but a vigorous grower.
Lakeside Midnight Miss
There are several Lakeside hostas that have shiny dark green leaves. If they're available in your area you may want to check them out.