The pie chart here is from the blog Unbecoming Levity — the author researched spellings of this Jewish Holiday in a OneLook.com dictionary search and plotted out which are the most common spellings. His conclusion: Hanukkah 39%, Chanukah 31%, Hanukah 7%, and about 16 other variants take the rest.
I just did a Google search of my own and in 2009 these were some results (I didn’t have the patience to drill down to the more exotic variations:
Publisher says
From Squidoo: