So with the release of Sun and Moon, that makes the grand total of main series games to 27, which is a lot. As the title states, What's your favorite Pokémon Game? (Main Series of Course) Personally, my favorite game is either Soul Silver or Black.
I would say Emerald for me! I like how both Aqua and Magma were threats, it introduced new characters, (like the Frontier Brains and even a new Gym Leader!) and of course, the Battle Frontier! B2/W2 is a close second. Like with Emerald, These games introduced so many things, like new cities, characters, Join Avenue, and the PWT!
I'd say either Diamond or Sun. The former because it was the first game I ever played to completion and Sun because I loved the change in gameplay. Very close behind the two of them would be White. The characters, story, Pokémon and villain were all fantastic in my opinion.
I think Emerald. I took a small break and missed RS and got back into the series with Emerald, it really was nice to battle against two teams and feel the fear.
I think the original Mystery Dungeon games (rescue team) will always be my favorite. I'll always be biased because of nostalgia. But as of late PSMD is up there too. But as far as traditional Pokémon games, probably Gold/Silver, or X.D.
Platinum is my solid favorite. It was the first one I got, and I have many fond memories of playing it. I was actually shocked about who the Champion, and it was just overall fun.
I'd say The Kalos Region's Pokémon X and Y because it has a real heartwarming story about a man you quickly meet and he makes himself sound like he knows he did something wrong
I would definitely have to say Soul Silver for me. Gen ll is my favourite gen, followed very closely by Gen l. I'd say this is my choice as it's a remake of my previous favourite game: Silver. Reasons: More Team Rocket fun 2 regions!! (I was really gutted when Sapphire followed and had only 1 region, I thought I was missing half a game!) Typhlosion (although admittedly on my first run through the game, when I was 10, I picked Chikorita. Not even sorry xD) Almost all other Pokémon from gen 2 are pretty badass imo Pokémon follow you! It's an amazing feature I wish they'd keep. It worked well in Yellow and again in HG:SS. Lance + Ethan team up in Mahogany Town was really exciting! Mt Silver, a great place to train post Champion! Fighting Dojo - I loved those rematches with gym leaders, with them not holding back (much stronger team) PokeWalker - Anyone remember that? I loved that device! The Magnet Train The Legendaries are really cool (Lugia was my favourite for years) 2 Starter Pokémon from 2 gens in 1 game! I had Cyndaquil and Squirtle The 3 dogs, especially Raikou, are really awesome! imo Battling Red on top of Mt Silver And many more reasons!
Silver/Soul silver / Gold/Heart gold probably. But I really enjoyed Omega ruby and Alpha Sapphire too. (Though I think I like PMD more than the main series games lately)
Omega Ruby is my fav, it's the first one I completed a national dex on. X and Y are close seconds for introducing Super Training which got me into competitive battling.
I'm going to divide my favorites between main games and spin-offs because of how close my favorites are in those respective categories. For the core RPG games, I'd say that my favorite has been Black. I love how the game took time to raise moral questions along with its cookie-cutter gameplay. For the spin-offs, my favorite is Explorers of Sky, hands-down. The fact that I can still pick it up, play it, enjoy it, and be challenged by it is amazing. I <3 it.