Happy ...

Hanukkah (9,330,000 Google hits without quotation marks, 9,140,000 with)
Chanukah (3,350,000 or 3,360,000)
Hannukah (3,270,000 or 981,000)
Hanukah (512,000 or 513,000)
Hanuka (281,000 or 243,000)
Chanukkah (275,000)
Chanuka (250,000 or 249,000)
Channukah (145,000)
Hanukka (108,000 or 103,000)
Chanukka (103,000)
Hannuka (75,500 or 77,700)
Channukkah (61,400 or 61,100)
Hannukkah (57,700 or 58,600)
Channuka (56,200)
Hannukka (49,800 or 49,600)
Khanuka (10,700)
Channukka (9,340 or 9,090)
Khanukkah (7,150 or 7,210)
Khanukah (4,870 or 4,890)
Khanukka (4,560)
Khannukah (969 or 957)
Khannuka (810 or 808)
Khannukkah (61 or 62)
Khannukka (6 or 5)

(inspired by a post from sandial)