Everyone has their Lego collections, whether or not sets are intact or in ruins for MOC-ing purposes. We all hold some if not all parts of our collections dearly. That being said, there are some sets and pieces that we may hold higher and closer to heart than the rest. It could be for sentimental purposes, or monetary value, or something more. What do you consider some of your prized collection pieces?
I'll start with a few of mine (I say few because I don't trust any of you with this info about me /s ).
For Bionicle it would probably be the Axalara T9 and Jetrax T6 just because they are so grand and display-able. Then again I also keep Toa Mata Nui, Brutaka, OG Makuta, Vezon/Fenrakk, and a few other gems out (ok, a lot of others, but that's for another time). Even for Hero Factory I keep Witch Doctor out as one of my favorites.
As for general Lego sets, a few have endured either because I like them so much or they're just too big to put away. For sentimental value I usually have out the Dinosaurs and Dino dinos, Buzz Lightyear's Spaceship, and Obi-wan's Starfighter from 2002. The other part of the list consists of large sets, including the Death Star, the 2005 Millenium Falcon, the Haunted House, and the original UCS Star Destroyer (unfortunately retired back to pieces). Oh, and how could I forget the Ninjago dragons, got to love those guys!
Don't even get me started on sets I haven't opened yet. That is a conversation that can't be stopped if it gets going.