Hi Charlie B!
Welcome to this Forum, and most of all Welcome to Thailand!
Phuket or Pattaya that's the question!? Two weeks in December is a short time! I guess it's nightlife and girls that draws you the most,right?
Then nothing can beat Pattaya! Thousands of bars and GoGo's with ten thousands of lovely thaigirls! Cheaper than Phuket, but the beach not as nice and the water not as blue compared to Phuket! More beautiful nature and islands around Phuket, beautiful beaches and stunning limestone islands like Pee Pee Islands and Phang-nga bay, and world class divingsites like Similan islands! Lots of nice girls and bars too, but only a few good GoGo bars. Prices are higher down here for example if you take a bargirl for ST(ShortTime) it costs about 1000 baht, and a GoGo-girl about 1500 baht it's almost double for LT(LongTime)! Compared to Pattaya were you will get a bargirl for 500 baht ST and 1000 baht LT, GoGo-girl about 1000 ST and 1500 LT. Beautiful and fit girls you will find at anyplace! If it's pure nightlife and thaigirls I would put my money on Pattaya any time! But if you want a combination of beatiful nature sceneries and nightlife then Phuket is at advantage! Up to you!