There are really several levels to think about when thinking about your favorite Star Wars gift. I have many.

There is the novelization given to me by my aunt in 1978.

The first Star Wars item my parents gave me (since it was forbidden this was huge but not at the top) a pair of Star Wars pajamas.

The first Star Wars present given to me by any girlfriend (that's always HUGE).

My favorite gift given to me was by my Aunt Barbara, around 78-79. It was a hand crafted ceramic R2-D2 she had made in ceramics class. While her classmates chose other items she went straight for the little droid to make. Not only that, but she decided, rather than make it a bank, she would get some Christmas bulbs, feed them up inside and give me an R2 light that would blink on and off. I loved it and still do. It sits in my room, with the original bulbs, blinking merrily away.
Blink R2 within Room Tour 6

Then you must also look at your favorite items that you have GIVEN as gifts. I've handed out many but my favorite of that lot is the time I gave away one of the Jedi Starfighters I had in my office to a kid whose Grandpa had brought him to the Children's Museum and it was closed. My office was nearby and they stumbled by as my door was open and I was watching AOTC. They asked about the museum and I had to tell them it was closed on Mondays, much to their dismay.
They ended up staying around and watching most of the movie. The young boy was looking at all the Star Wars stuff I had in my office and seemed mostly interested in the starfighter. As he ran around 'flying' it I asked if he would like to take it with him. He was amazed and said he just couldn't take it. My reply was a simple, "ok, then how about this one". I handed him the other starfighter I had but Obi-Wan was piloting this one.
As his grandfather was starting to deny the gift, I told them that I had plenty and if it was something that he'd really play with, I would be more than happy to part with it.
I got a huge thank you from the little boy and a thanks from the grandpa. It was funny to hear the made up sounds of the starfighter as he 'flew' it through the halls and out the front door.