Well, my recent backed Kickstarters will bring in some collectibles: I have The Guide to Glorantha two volume set, and will be getting John Tynes’ Puppetland and Mage: The Ascension Quintessential edition (with a lenticular tarot card on the cover!) along with new editions of Feng Shui, Call of Cthulhu and Paranoia on the way.
For D&D, I just have the new 5th edition books and the Starter set. That may be enough for me though, unless somebody produces a truly excellent campaign or adventure series. I’m really happy with them. Like Traveller, my go-to game for Science Fiction, the corebooks are enough for a lifetime of gaming in themselves. In a sense, specific to action genre emulation, Feng Shui acts as a third game for ‘pick up and play’ as something a bit different, but instantly easy to run.
I have my ‘Chaos trilogy’, as I call them - RuneQuest 6 (leather hardback, in slipcase along with the Glorantha stuff), Call of Cthulhu (30th Anniversary + Masks of Nyarlathotep; 20th Anniversary and 7th Edition on the way) and Dark Heresy (2nd Edition; Warhammer 40KRP). They don’t have shared backgrounds but all are themed on dark Chaotic forces in one way or another and take place in the mythical past, shadowy present and grim-dark far future respectively. And use percentile mechanics. So I see them as a loose trilogy.
I have Vampire: The Masquerade and Werewolf: The Apocalypse in their 20th Anniversary guise, to go along with my favourite WoD game: Mage: The Ascension Quintessential edition to make yet another trilogy (the others in the series I can take or leave). Mage may ultimately prove to be my overall favourite, but I’ve yet to receive it!
Other games in my collection, which feels quite complete to me these days include: Doctor Who: Adventures in Time and Space (50th Anniversary), The One Ring RPG, Star Wars: Age of Rebellion (as it stands, although I kinda miss the old D6 system and I’m in two minds whether I really want to get the other games in the series) and some novelty games: The Extraordinary Adventures of Baron Munchhausen (leather cover), HoL: Human Occupied Landfill and Fiasco, with Paranoia and Puppetland still to be added.
As I said, my physical collection is feeling quite complete for my lifetime these days. I still like adventures and supplements but these I get as pdf for the most part.