It's a tie between Easster and Christmas for me.
Easter because I love bunnies & chickens, and all the springy smells.
Christmas only made the list this year. Since my parents got divorced (2009), I've been way more excited to make Christmas amazing for my family (father, sister & husband). I really love it!
Halloween is followed closely, because it takes the attention away from my birthday (November 1st) which I can't stand.