My literal Christmas list this year, which I came up with eventually after people insisted on getting me something:
1. New strap for my bass guitar. The old one keeps falling off while I'm wearing it. Preferably the thicker kind, because the thinner kind isn't strong enough to support the weight of the guitar, and it hurts your back more. Also, no flashy designs, I don't need flames drawn on it.
2. One of Keirsey's books. Typology stuff.
3. An HBO mini-series. I don't know if it's been put on DVD, and I haven't looked for the price, so basically I told them to use their judgment in regards to price.
4. If they need to get me another gift, two Metallica CDs that I can live just fine without. I kind of like them.
Around a few years ago, I started realizing I had most of the material stuff I wanted. (No, I'm not rich. Lucky to have nice parents, though.) When my parents asked me what I wanted, I said, "Nothing, I'm fine with what I have." It sounds nice, but I mainly meant it in a serious way.
I don't know how this could help you out, as it seems really dependent on personal taste. The trivial presents, that is. The much more important gift is you spending time with him.
That's the tricky part about getting him that one thing he's always wanted, that he's been talking about. He might have already bought it himself, or planned to buy it.