1. Ornaments - get one from each trip (and have an ornament tradition in our family).
2. I have this perfect deep bowl from Japan (nice blue on the outside). I got it, I believe, in 2002 (it could've been the 00 or 01 trip, though) and it's still the best bowl I have (it is the best bowl for curries, pasta, noodle dishes, etc). Sadly, I've not found these since then (likely because I've been there relatively infrequently).
3. We have a few other not as nice dishes, as we've started a tradition of bringing home a dish from a WDW trip and they get used in the normal course of a week and it's a nice touchstone. (ETA: I passed up on a great bowl set, from F&W and the Remy challenge, and I'm super disappointed because I came home without a dish of any sort - not many options that worked for me. So, if you see something you like, go for it! I really wish I had gotten those F&W dishes!).