Many that have already been mentioned:
American Gods
Little, Big
Jeff Van Der Meer's Veniss Underground stories
Jonathan Strange and Mr. Norrell is my favorite, but you've already read it.
The Anubis Gates by Tim Powers. ANd if you like that, you can try his The Stress of Her Regard -- he's a hit-and-miss author for me, but when he hits he's the most fun ever.
The Last Unicorn, Peter S. Beagle
Dark Sister, Graham Joyce (Joyce can be a little, as you might expect from the title, dark. Wonderful, though)
for just plain funny literary-spoof fantasy, you cannot do better than the Compleat Enchanter, by L. Sprague De Camp and Fletcher Pratt. Although Gaiman/Pratchett's Good Omens is pretty hilarious as well.