What's your Favorite Pokémon Generation and why?

i really like gen 2, mostly bc i like the starters and the player characters lolol. typlosions my favorite pokemon its SUPER COOL! φ(*￣0￣)

This is mostly based off of how much fun I had playing each gen, not
necessarily off of objectivity. The exception to this is Gen V, which I
truly consider to be the peak of the series. I won't be rating Gen II
because I haven't played it.

1. Gen V - They polished up the
   games a lot with this generation. They took more risks as well with how
   they wrote the story. Directly addressing the whole "Pokémon is
   basically dogfighting!!!11!!!" thing people like to bring up was really
   interesting. I loved the characters since they did something in-depth
   with them. I think the only thing that was really a problem with these
   games was how the sprites and 3D models didn't fit well together at
   times. Still, I rank them as the top games. IMO this was Pokémon at its
   peak.
2. Gen IV - This one is second best to me due to nostalgia
   and because this generation contained the HeartGold and SoulSilver
   remakes (probably the best remakes ever put out by Game Freak). This is
   the generation I started out on. I should've started with Gen III TBH,
   but I was late to the Pokémon party. The mixed usage of 3D models and
   sprites worked well together this time around. It's because they weren't
   trying to emphasize the 3D and instead used it as an enhancement. The
   remakes were excellent, packed with content, and with the ability to
   have Pokémon walk with you. Diamond, Pearl, and Platinum were also very
   enjoyable for me to play. Pokémon Ranger: Shadows of Almia also came out
   during this generation, and I consider that to be the best of the
   Ranger games (though my favorite is the original Pokémon Ranger).
   
3. Gen
   VI - The jump to 3D was very exciting at the time, but now I have to
   ask myself if it was truly worth the price we had to pay to get there. I
   love X and Y. I had a lot of fun playing it. In fact, I put 70 hours
   into it before even beating the game. It was the first game I ever
   pre-ordered and it's what made me go out and get my special Pikachu
   edition 3DS XL. But I consider this to be the beginning of the end for
   the series. They never tried to hit the peak of storytelling they hit in
   Gen V. These were good and fun games. It's a too bad this was where, in
   my opinion, the series began to lose its way. Seeing Hoenn remakes was
   great though. These remakes added soaring around in the sky, which I
   loved to pieces and still do.
   
4. Gen VII - The graphics got
   cleaned up here and they shook up the formula
   for how a Pokémon game is played. I respect this a lot. I haven't
   played these games a lot, but I already want to stick them above Gen VI
   (as much as I love X and Y) due to the improvements and the gutsy
   changes to the formula. It's not often Game Freak takes risks like that.
   Objectively, I'd rate this above Gen VI, but it goes below it because I
   didn't enjoy it as much.
5. Gen III - There's a lot of things I
   like about Gen III, but I just... don't have as much fun when I play
   them. Maybe I'm spoiled by future generations. Connecting with these
   games is very difficult for me. I don't get immersed in them. Maybe I
   just need to chip away at Emerald some more, who knows. This is the best
   way at the moment to experience Gen I (I refuse to recommend Let's Go
   Pikachu/Eevee), which is sad because getting copies of these games is
   very difficult and expensive, with fakes saturating the market. This
   generation also brought in Pokémon Ranger, which was the game that
   introduced me to Pokémon in the first place. So, despite it ranking low
   for me personally, this generation is still very important to me.
   
6. Gen
   I - I respect this generation for what they introduced to the world,
   but these games suffer from serious issues, from type balancing to the
   way it was programmed. I'm not going to complain about graphics though
   because that's just ridiculous to gripe about. There are some things I
   like about it though. These games have a distinctly different feel to
   the rest of the series. There's something just... darker about them that
   I can't fully explain. It somehow feels a bit more grounded as well.
7. Gen
   VIII - Screw this Gen lmao. I can't even write about this generation or
   I'd be creating a video essay with how bad it is and how much I hate
   it. It's Just Bad.

Gen1, I only played the gen1 games

I'm particularly fond of gen 5 and (brace for an unpopular opinion here) gen 8, but I don't particularly hate any Pokemon generation.