I tried to answer one of those "pick one game for each genre" polls.
The problem was, I tried to answer honestly. So, knowing that most games that do well at representing a sub-genre actually suck at representing other sub-genres within the same genre (case in point: DCC is great for S&S, but trying to run a high fantasy campaign with it might require...dropping some rules, at least), I tried to answer by sub-genres.
Then I realised that by answering honestly, I'd created such a huge list (shown below - though I wouldn't blame you if you haven't read it) that it totally defeated the point, with the point AFAICT being "tell us which games you would return to time and time again". (If you have 50+ games, you can afford to switch between them, so even if a system starts grating at you after a while, it doesn't matter. You can just switch to something entirely different for a change, then revisit it after a significant pause.)
So I went to thinking: do we really need such a huge number of sub-genres?
Furthermore, I was thinking, different authors writing in the same sub-genre feel really different. Sometimes, their own works in entirely different genres might well feel closer than another work that shares a sub-genre.
Should I just go to my old system of "genre classification"? It only allowed for, like, 5 genres: Detectives (no matter anything else, if it's about a crime, it's listed here), Martial Arts stories (happily lumping swashbuckling and wuxia together), Fantasy (anything with magic), Historical (including present-day, as long as there's no magic), Sci-fi (anything in the future and/or speculating about advances in technology - so I used to happily lump together Asimov's "Foundation" and "Blood music"). Then I specified the "flavour" by adding the author's name.
So, Blood Music would be "Greg Bear SF", while the Foundation series would be "Isaak Asimov's SF". LotR would be "Tolkien's fantasy", while "Earthsea" would be "Ms. Ursula's fantasy", and Amber would be "Zelazni's fantasy". Always worked for me and my friends...
I'm now trying to remember why I gave up on it.
Still haven't found an answer to any of the above questions.
(If you care to know: At the end, I just shrugged and posted "I pick my own homebrew, since I can adapt it for everything". Of course I can, it's my homebrew. Switching it to emulate another system's qualities wouldn't even be a houserule - more like an update and going from edition 0,755 to 0,756...so while technically it's true, it was also a not really helpful answer.
Though, to be fair, I should have posted "Traveller 5, some other edition of Traveller, Mythras, Pocket Universe, BoL and my own homebrew" instead. Ah well, live and learn!)
The huge list that prompted my considerations:
4 colours Supers: 4 Colours. Doh!
Gritty supers: Wild Talents
Hard SF: 2300 AD
Ecologist Science Fi- Blue Planet
Space Opera: Traveller 5
Post-humanist SF: Eclipse Phase or Transhuman Space, leaning towards the latter
Cyberpunk: Cyberpunk 2020
Neo-Cyberpunk: Fates Worse Than Death with BtEoM supplement
High Fantasy: Godbound with Scarlet Heroes for the mortal level.
Romantic Fantasy: FUDGE with the HeartQuest Shoujo supplement.
OSR Dungeon Crawl: DCC, doh!
Non-OSR Dungeon Crawl: 13th Age
Victorian Gritty Fantasy: Backswords and Buckles
Fantasy Africa: Solomon Kane
Movies-inspired Swords and Sorcery: BoL, latest edition
Novels-inspired S&S: Mythras
Exalted Fantasy: I said Godbound already, let's give Ex3 a chance
Ancient World Fantasy: Mythras
Swords and Sandals: Zenobia with 43 AD and Warband (seeing as how they are variants of the same system, I treat themas supplements).
Swords and Planet: Pocket Universe, with Bethorm as a setting supplement
Gritty Novels-inspired Swashbuckling: Flashing Blades with the High Seas supplement
Funny Film-inspired Swashbuckling: Honor+Intrigue
Fencing Pirates: Le Pavilion Noir (with the fencing supplement, of course).
Anthropomorphic Fantasy: Ironclaw, with the Jadeclaw and Bone and Ivory supplements, and Usagi Yojimbo as a supplement for the Japan- analogue.
Fantasy in space: Hellas
Arthurian Fantasy: Pendragon 5.1
Post Apocalyptic Fantasy: Earth Dawn 2e from FASA...the edition choice is just "because I already own it".
Mecha, Monks and Ninja: TBZ, of course.
Espionage: Night's Black Agents
Techno thrillers: Millennium's End
High-Powered Wuxia: LotW
High-Powered Wuxia with focus on finding legendary weapons: Weapons of the Gods
Low-Powered Wuxia: Qin with all the supplements
Kungfupian, preferably generational: Tianxia
Wuxia with Xian xia: Wandering Heroes of Ogre Gate
John Woo movies, with or without talking apes: Feng Shui 2
Fighting Games emulation: Fight! The Fighting Game RPG
Shonen: Fight, but with the Shonen supplement
Boxing/MMA Stories: Contenders
General Martial arts stories: My own homebrew started as a way to do this, and find it does so nicely already.
Urban Fantasy: Witchcraft
Vampires-focused UrbanFantasy: Vampire City
Summoners-focused Urban Fantasy: Sorcerer
Dragons-Focused Urban Fantasy: Fireborn
Historical games: Mythras or my own homebrew
Pulp: Savage Worlds with Thrilling Tales
Noir: A Dirty World
Whodunit Detective Stories: Fear Itself
Medieval Whodunit: Maelstrom Domesday
Heist Stories: Skulduggery RPG
Western: My own homebrew makes it equally easy to play gun duels, as presented in the fiction (and unlike how they probably worked),or the way they probably happened
Slice-of-Life Anime emulation: OVA2e
Dimension Hopping Reality Bending Adventure: Amber
Time Travel: my own homebrew. I don't think it's good enough yet, but I can adjust it - and no game I know does a much better job, so I'd rather trust myself.
Slaughter Horror: Snuff: The Downloads of Death
Mythos Horror: toss if a coin between CoC 7 and Delta Green
Mystic Horror with Mad Wizards: Unknown Armies 3e
Fairy tales: My own homebrew or Mythras
Trade Empires in Ancient Rome: Worlds Apart
Trade Empires With Flying Ships: Volant
Yes, I know. That's a huge number of systems. That's what bothered me, too: do we really need that much?
My feeling is that the answer should be a resounding "no". But how do we change that?