When people tell me "Happy Holidays," I respond with "Merry Christmas." If I have to explain why, it's because I'm letting them know I believe in Jesus Christ. While I do think it is slightly absurd that this moniker has somehow become politically incorrect (why does the absence of religion in an Atheist's life trump the presence of religion in a Christian's life?), I do love how it now involves a little missionary action. I don't say it to convert anyone, but to spread a little faith around. If someone were to tell me "Happy Hanukkah," I would be delighted to learn of their faith through two simple words. It means they have included me in sharing their beliefs. I don't think it is anything less when a person says, "Merry Christmas."
However, I don't think this phrase should ever be limited to Christians. Besides, no matter how many people try to commercialize the biggest holiday of the year, it will always remain a fact that it is Christmastime and that Christmastime is celebrated in remembrance of Christ's birth (I don't care about the origin of the holiday. This is here and now we're talking about. We all know how it started and it's obviously changed into something completely different. That argument has expired.).
I don't get offended when I hear "Happy Holidays." But I do get irked when people fight to take down nativity scenes and banish songs about Christ from the radio. In my very personal opinion, I think the entire reason why the ever-so addictive "Christmas Spirit" survives is because all around us are hymns about the Savior. I think the reason why people are more giving at this time of year is because people act on the desire to give. I think if you took away the center of the holiday (Christ) and the pleasure of the holiday (giving to others), the meaning of "Christmas Spirit" would change completely. Instead of child-like wonder, compassion, and happiness, it would be nothing but stress and anxiety.
So to all of you wonderful people out there, shout the holiday greeting that best fits your beliefs, whether that be Christian, Jewish, Atheist, Agnostic, etc.
As for me and my house, we will shout, "Merry Christmas!"