I don't own anything super rare, but if I had to choose 5 favourite things it would be these:
Loose R2-D2 pop-up
He isn't much to look at and doesn't have his sabre, but this is one of my few remaining childhood figures that I only found fairly recently. I chose this one in particular as it's a pretty sought-after loose figure, so it's cool to still have my original one.
Kenner 21 Back Luke X-Wing
I have owned this MOC for over 20 years. It was my "grail" piece in the 90s, Luke X-Wing was my favourite figure as a kid and it blew me away when I saw this for sale in a shop in Poole in about 1995. It cost £100, and I was about 13 at the time so had to put a £50 deposit on it and pay the rest off weekly. It was the best piece in my collection until the internet came along.
I almost lost it in 2007 when among many other MOCs it was stolen in a burglary, but luckily when the thief was finally caught 5 years later thanks to our own Joe_O, this is one of the few they had not sold (probably because the big crease makes it easily identifiable) so I was eventually reunited with it. This is one MOC I would never sell.
Trilogo Luke Bespin
I got this from Vectis a couple of years ago. No cool story behind it, and it wasn't a great bargain, it's simply one of my favourite figure and cardback combos. One of the best looking MOCs IMO.
MISB Bi-Logo AT-ST
This has surely got to be one of the coolest toys in the whole line. It is fairly screen accurate and has great play value. I also love the box artwork and photography. Having this on my shelf takes me straight back to the 80s!
Trilogo Leia
This is a cool MOC in most people's book, but it's extra special to me as it was an "in the wild" find and took many weeks to arrive from the US, so it was a relief when I finally got my hands on it! Big thanks again to Joe for the introduction, and to Iain for shipping it to me.