Don't get me wrong. Christmas is a more special holiday for me, bringing me close to family and loved ones, plus having an obvious religious significance. I look forward to each Christmas season while July 4th just sort of happens.
The thing is, looking back at Christmases - and Thanksgivings - they all sort of run together and get difficult to distinguish. Except for one here or there, my Christmases - and Thanksgivings - were largely spent with the same people, at the same locations, eating the same meals. Even when I started spending holidays with in-laws, after a few years they are hard to tell apart (which Christmas was it that I was snowed in at Chicago? Or was that a Thanksgiving?).
July 4ths, on the other hand, are easier to tell apart because they have been more unique, spent in different locations with different people. I spent one watching fireworks on the D.C. mall (the most spectacular fireworks I have ever seen), another from a rooftop in Austin, another at Disneyland. I spent one running from summer camp counselors who were trying to chase down the campers who snuck out of their cabin to shoot off illegal fireworks (they never caught us). And so on.
So looking back, July 4ths are more unique, making them more memorable. However, I think going forward that is changing due to having a daughter. I think the rolls may start getting reversed as I start experiencing Christmas through her eyes and I become more limited to where I can go party every July 4th.