Generation 6

Generation 6 was the revolutionary leap for Pokémon to become three-dimensional. This had the unfortunate side effect of severely limiting animation, dulling colors (ruining some shinies in the process) and forcing all flying Pokémon to be forever stuck in flight. Generation 6 also added the new Fairy Type, providing an answer for incredibly strong (overpowered?) Dragon Type Pokémon. These games also introduced Mega Evolution, allowing certain Pokémon to evolve again during battles only. This is considered the start of "gimmicks", mechanics introduced for one or two games only, never to be used again. Generation 6 has Pokémon X, Pokémon Y, Pokémon OmegaRuby, and Pokémon Alpha Sapphire. X and Y are set in Kalos, aka Pokémon France, whereas OmegaRuby and AlphaSapphire are remakes of Generation 3's Ruby and Sapphire. I am, admittedly, not very impressed with Generation 6. X and Y feels a bit flat, and while OmegaRuby and AlphaSapphire are good games, Emerald is the better game of the trilogy in my opinion, and did not receive a remake. That said, they are perfectly fine games.

Games

Pokémon X (x2 USA, x2 PAL, x1 Digital), Pokémon Y (x1 USA, x2 PAL, x1 Digital), Pokémon Omega Ruby (x2 USA, x1 PAL, x1 Digital), Pokémon Alpha Sapphire (x2 USA, x2 PAL, x1 Digital)

Shiny Pokémon

Generation 6 did do one thing that I approve of, though. The original Shiny Odds of 1/8192 was halfed to 1/4096, which can be lowered even further with the Shiny Charm to 3/4096 (roughly 1/1365). In addition to several different ways to hunt for Shiny Pokémon, Generation 6 is arguably when Nintendo really started paying attention to the Shiny Hunters.

Wingull Sprite Wingull (x1), manaphy Sprite Manaphy (x1) (I am unsure of the legality of this Manaphy), Explou Sprite Exploud (x1), Jolteon Sprite Jolteon (x1), Treecko Sprite Treecko (x1),
Poochyena Sprite Poochyena (x1) Weedle Sprite Weedle (x1), Zekrom Sprite Zekrom (x1) (I am unsure of the legality of this Zekrom), Luvdisc Sprite Luvdisc (x1), Whiscash Sprite Whiscash (x1),
Octillery Sprite Octillery (x1), Skrelp Sprite Skrelp (x1), Gulpin Sprite Gulpin (x2),
Mareep Sprite Mareep (x1), Hoppip Sprite Hoppip (x1), Zubat Sprite Zubat (x1),
Poliwhirl Sprite Poliwhirl (x2), Swablu Sprite Swablu (x1), Nosepass Sprite Nosepass (x1), Bergmite Sprite Bergmite (x1),
Pancham Sprite Pancham (x1), Cacturne Sprite Cacturne (x1), Espurr Sprite Espurr (x1), Yanma Sprite Yanma (x1),
Beautifly Sprite Beautifly (x1), Plusle Sprite Plusle (x1), Girafaig Sprite Girafarig (x1), Sawk Sprite Sawk (x1),
Poliwhirl Sprite Tyrogue (x2), Haunter Sprite Haunter (x1), Azumarill Sprite Azumarill (x1), Camerupt Sprite Camerupt (x1), Cubchoo Sprite Cubchoo (x1), Eevee Sprite Eevee (x1), Ralts Sprite Ralts (x1), Scraggy Sprite Scraggy (x1)