BattleTech RPG spinoff Mechwarrior was still very much a war game that just happened to have tabletop RPG elements in its first edition, and it was not well optimized for anything other than small unit combat. Things improved somewhat in the second edition, but it was finally around its third edition that the game figured out how to let its players in on its Humongous MechaSpace Opera setting as more than just another soldier in a drawn-out fight full of record-keeping, calculations, and statistical minutiae, as the setting at the time also bloomed into arguably its most famous timeframe, from the Clan Invasion up until the eve of the Fed-Com Civil War. Conveniently, the game also had rules for people who wanted to play in older periods of time as well, and so generally appealed to most of the growing RPG fanbase.
Magic: The Gathering was always a fun game, but the point at which it "grew up"—simplifying rules baggage, gearing toward tournament play, improving art standards, and kicking off its longest-lasting storyline — was the Mirage set. Probably not coincidentally, this was the first set that head-designer-to-be Mark Rosewater worked on.
It wasn't until Ice Age that Wizards of the Coast got the numbers right for card value, rarity, and the yearly release cycles with sets.
Nobilis was always well thought of by its fanbase, but it's the enormous and gorgeous second edition Great White Book that people generally associate with the feel and appearance of Nobilis.
1st Edition (ie: Rogue Trader) Warhammer 40,000 was essentially WarhammerIN SPACE. 2nd edition refined the concept from being space-elves, space-undead, space-orcs, space-dwarves to being races in their own right, but it took until 3rd edition to expunge the silly elements and turn it into the GrimDark nightmare it is today, highlighted by a major shift in painting styles from technicolor schemes and often awkward banners/slogans to a more gritty and realistic style. 3rd edition also significantly simplified and streamlined many of the gameplay elements that were inherited from its WHFB precursor.