Well, my brother is eight, (just turned) and he started watching them around 3. Now whats intresting, is, for a period of time, all that existed to us was our 10 year old copy of the faces FS tapes...we'd watch that EVERY SINGLE night! I knew there was the new star wars movies (I saw TPM in the theater,when I was roughly my brothers age) but I never really was intrested. Then I got the Musical Journey DVD! I was so hyped up, seeing the star wars movies I knew, but seeing them "digitaly Remasteres" and seeing that new end sequence with the new inserts! I was crazy! I then started on a DVD rampage. I bought Ep.I, Ep.II, Clone Wars.......I was still a novice to SW.
My brother, saw Episode III in theaters, and his favorite movies are ROTJ and ROTS, with ROTJ being his #1.
Then June (2005) came around, and I bought the 2004 Editions. I was happy, I watched them, and I really liked the way everything looked fresh and new...infact, I was sick (with a fever) when I went to target-lol-so I bought my set, came home, barfed in the toilet, put in ANH, layed in bed, and put on some head phones and the directors commentary. I watched all 3 fims that afternoon.....well, October comes around, and Im into OT.com....
My brother got really into it, hell he still is into it, and me and him sat and watched the entire movie Building Empire. And he really liked the alternate angles and takes, and diffrent dialouge sounds, etc. He hated that commentary-lol
My dad says anyday is a good day for a good steak.

I say, any age is a good age for Star Wars-lol