How do you guys feel about how did the Wh40k lore changed over the years? Which is your favourite edition lore wise?
When I started playing 40k in the early days of v3 lore was very basic. All the cornerstones were already there, the space marines and their primarchs, the Emperor, the Heresy, Chaos and warp travel, most of the factions we know, etc. However it was all very mysterious : the Heresy was a long forgotten war with only major events remembered, the Necrons only appeared as a crude drawing in the "unknown species" page of lore with a "???" for caption - they were, like the Legion of the Damned, hard to find miniatures many player did not even know about. Lore was sprinkled here and there, in White Dwarfs and mostly in books from v2, some never translated in my country and all never ever reprinted. V3 was also the time of retcons, it was a major rewrite of 40k, dropping some 1st and 2nd editions armies and lore to focus on a darker and more coherent core, trying to consolidate the giant sci-fi ripoff that it was into an original universe. I believe that John Blanche and Jes Godwin are almost solely responsible of 40k vision and success and without them it would still be Vietnam War in space.
It also was a bit tongue in cheek, Andy Chamber was making funny faces on pictures, there was a double-page article at the end of the rulebook called "The ultimate secrets of the Galaxy revealed" that were some light-heartened design notes, along with an uncanny drawing of a space marine with a smiling-bird-like helmet. The "Chapter Approved" book that appeared mid-v3 was crammed with rules and funny articles (yes, funny like laughing-out-loud funny), selected reader's mail and the vehicles design rules illustrated by an old Rick Priestley grav-tank made out of a deodorant bottle (and the Machine Spirit was but a rule that allowed Land Raiders to move and shoot even if the crew was incapacitated).
It was all fun and kind of absurd ("there is only war", it did had a funny tone at the time), and only the incredible art was giving soul and life to the underlying silliness. It was a great background to the miniature games that was at the time the only focus of Game Workshop. There were no successful video games nor books, and nobody was interested in the lore itself if he was not already a player.
By the end of V3 the necrons appeared as a regular army, moving from being mysterious invincible robots totally lifted from Terminator and without any lore to space-Egyptian with some boring backstory involving Ancients, unknown at the time, and C'tan who, from the mysterious beings responsible for the Callidus Assassin sword (which was at the time the most deadly weapon around) became some giant space ghosts with ludicrous stats.
Game Workshop also tried plot advancement at the end of V3 with the Black Crusade campaign which was a total flop, but was one of the first tentative to milk the lore for profits. I stopped playing around this time and had to switch to Fantasy Battle, which I never really enjoyed. Soon after the first Dawn of War video game hit the shelves and introduced a whole new population to 40k, and it became a franchise.