Hmm, good question.
I think these things are pretty dear:
Accutron Eagle Chronograph - Wife gave this to me for our 25th wedding anniversary (now 31 yrs). I polish metal, so mine is fully polished stainless:
My '66 Triumph Bonneville bobber. This took me four years to rebuild, I took the cost-effective route, swap meet parts, etc.
A few guns. I've had this Ruger since I was 18 years old. My dad bought the Single Six at the same time, I now have both:
Mk II, nothing special, but a hoot to shoot
Single Six
My SP101, fully polished stainless. Actually the LL Bean "Flying Tigers" jacket it is sitting I've owned for 15 years and it's a pretty cherished item as well.
I recently sold my beloved 2002 Bonneville America, so the wife and I could enjoy a convertible. We bought this '79, so that's a new item, hopefully to be enjoyed for many years.