Are you looking for large capacity or something with a map window? I've got a pretty slick HARD tank bag that I got for my V-Rod.
Shook Designs Speed-Pac Hardshell bag
I've got a spare airbox cover (where the tank is on a traditional motorcycle), that I'm going to bolt it to some day. My V-Rod is my "beater", so I ride it to work more often than any. It's large enough to pack a lunch, and bring home my dirty work clothes. It also doubles as a backpack, but I've never used it as such.
They offer magnetic and strap options. You'd probably have to stack some foam spacers to get it to clear your console on a Road Glide though.