Best characters not in the show? [Spoilers Extended]

Also, characters who may have been in the show but we're far less important.

A few of my faves: Strong Belwas Victarion Greyjoy Illyrio Mopatis (although in the show, his role was reduced) Wyman Manderly (same as above) Septon Meribald (ignoring Ian McChane plays a Meribald-type role at one point) Devan and Gemma Lannister

I'm probably missing some other gems.