There was an an interesting list posted by Wisebread today on items that make more sense financially to buy used than new if you can.
So if you are in the market for any of the following, you may save more money and get more value for your dollar if you buy used rather than buying it brand new:
DVDs and CDs
Special Occasion and Holiday Clothing
Games and Toys
Maternity and Baby Clothes
Pets! (Adopt from an animal shelter!!)