Disclosure: I received complimentary products to facilitate this post. All opinions are my own.
Zazzle is currently in the middle of their 30 Day Giveaway of some of the great products available. Plus, each day you enter, you'll receive an email the following day for 30% off the previous day's product in case you don't win but still want it. Each day you enter, you'll get an additional chance to win the Sweepstakes Grand Prize $1,000 Zazzle shopping spree.
They have nearly everything imaginable in terms of products that are perfectly personalized for the people on your list. I was able to find these great Frozen Sisters Forever shirts for my daughters and a Gamer/Engineer shirt for my brother. Really, the only downside of the site is that there are so many products available it can take a little bit to search for exactly what you want. You can also choose options like color, which isn't available as an option at all sites.
Shipping was very quick - I had my products in a timely matter. I'm happy with the quality of both the apparel and the printing, and I can't wait to give them as gifts later this spring!