The most valuable thing stolen from me? Hm, jeez this is going to be a bad one(s):
I'd say admiration/respect of the patriarch was taken when my originally absentee father tricked my sister and me into thinking he was a good guy and basically giving custody of us to him and his mother. That lead to a long dark history that is still writing itself.
Faith in adults in general went away when my third grade teacher, Ms. Thompson, Rm. 204, verbally tore me to pieces with personal comments about my insecurities and held me up for ridicule to the rest of the class for wanting to participate when no one else was volunteering. Until then I thought most adults, teachers specifically, were there to guide and protect almost infallibly. Afterward I knew they could be (and probably were) assholes too.
I lost trust during the many many years my half brothers stole many of my things. A decade or so of desperately trying to figure out how to protect my stuff because my father not only allowed the thefts but would often lie about buying the things for them himself so they could keep it all. I don't speak to those two half brothers anymore.
I guess childhood innocence was stolen the night my mother's drunk boyfriend (father of half of my siblings) tore my clothes off of me in rags and beat me with his fist and a whiffle ball bat on the living room floor while my younger siblings could only watch sadly. I think I was ten. He did it because I accidentally cracked the drywall in the kitchen.
Care for my neighbors was gone when one of the families on my street began breaking into everyone else's house. I didn't even hear about it until I came home from a weekend out in 2008 and found my living room and storage room ransacked. They also stole a large album of Pokemon cards which I cherished because I really enjoy collecting and organizing things like that, but also because the bulk of my collection came from and was started by a person that I cherish very much. The cards were in pristine and cared for condition but were basically worthless because of the nature of retired cards and competition. This means they probably ended up in a dumpster or destroyed by some kid that couldn't have cared less.
Oh had the future I'd planned taken when I caught mononucleosis in college and the doctor told me to quarantine myself and not go to class and infect others. Missed my midterms and went for a medical withdrawal but the same doctor refused to sign the form. I lost my scholarship and had to drop out right before my senior year.
Monetarily though, the most valuable thing stolen from me was a car in 2004. I bought a car to learn how to drive on a Saturday. Paid the complete balance for it on Monday and brought it home to practice the next weekend. Friday morning it was gone. I owned a car for four days. It was never found, I still have neither "road confidence" for driving nor a license. I guess that's more than money-wise as well because it has stunted my independence by quite a bit.
I know, I know, poor me... just answering the question though. Plus I figure I'm still alive, I have the greatest best friend that anyone could possibly hope for, and there are certainly a lot of people much worse off than me in the world and they're still powering through so I definitely should too.