My earliest childhood memory was of the Mattel Shogun Godzilla, sadly I never personally owned one, but I do remember seeing them in stores.
I am a child of the late 70's/ 80's and loved all the brands, but early on, my parents asked me to dedicate myself to one line, instead of smattering my interests across them all, so consequently I loved all the animated series, but only ever had toys of MOTU (He-Man), and later Transformers. I decided to grow my adult collectivization on when eBay was in it's infancy, and getting them at conventions wasn't insanely expensive. By 2006 I had managed to obtain pretty much every MOTU, Transformer, Bandai Godzilla, and Gundam MSIA I wanted, and even some Japanese ones I didn't even know existed as a kid. Sadly I had to sell them all later that year. I was out of the toy collecting....
Since my kids have grown, they've gotten a few toys here-and-here but no serious collecting. Until I was sucked back in by the Transformers Generations line in 2015 "Combiner Wars" -This represented the very best of what I loved about the original Transformers, but with modern toy engineering. For the past 3 years I've enjoyed collecting the various Transformers Generations lines (Combiner Wars, Titans Return, and Power of the Primes), with my kids. I don't plan to try to get back all the things I sold back in 2006, It would be nearly impossible. i just enjoy what I have now.
As an interesting parallel, in 2016 Hasbro remade the largest Transformer I owned as a kid Fortress Maximus:
I got mine as a gift in December of 1987, and owned it until Summer of 2007. So that was nearly 20 years. When I gave my son the new one in the Summer of 2016, I said "See if you can do better"