If you only go to one, make it the
MVMCP.
Tinkerbelle flies at each party as well as the 360 degree fireworks.
When we were there in 2002, instead of Tink, they had Rudolph.
We did both this past Christmas trip, and I shot video at the party to get Tink, the show, and the special fireworks, and then took still pictures on the regular night. I can't get enough, so I'd suggest you do both if it fits with your plans!
Oh, and a shameless plug for votes on the Community Board (not for me, but for your participation):
what would you want to be bribed with? Lots of Gifts called the 12 Days of Disney, a trip for a Make A Wish child, or a week's trip for you to WDW? Vote now!!
http://www.disboards.com/showthread.php?t=828973