First let me say thank you so much for these contests! Some amazing prizes and I've enjoyed reading everyone else's answers. I love that you guys are such a big part of this community!
Now on to today's question: For me it depends on the reason for celebration but, I usually grab something I consider to be "rare". To me it makes the experience that much better. I have only been smoking for about 7 months so my reasons to celebrate haven't happened that much.
I did smoke a BOTL 2012 on my birthday. I remember that cigar like no other. It was the first BOTL I had smoked and it was gifted to me by Calgon! That is when I knew this place was something special.