My first Pokémon game was Pearl Version, and Platinum is my personal favorite game to this day. However, even though that's where I started playing Pokémon at age ten, I had been a fan of the franchise as a whole for much longer, as long as I can remember, in fact. I do look back at Sinnoh with nostalgia, but not an extreme amount more than Hoenn, Johto, or Kanto. My first starter and first ever Pokémon was Turtwig, but it's only my fifth favorite starter Pokémon, behind Charmander, Froakie, Rowlet, and Torchic. My overall favorite Pokémon is Giratina, which, while it is from Sinnoh, I decided it was my favorite before I ever touched a Pokémon game, so Pearl Version had little influence on that, though, Platinum's story and introduction of Origin Form did cement its place. As far as overall regions go, Sinnoh is about tied for my favorite with Hoenn. To summarize, I would say that Sinnoh and Gen IV as a whole was important to me, but not so much so that it is held above all else.