These days there are so many people bashing Generations 3/4 and afterwards of Pokemon with the basis that Gens 1 and 2 were the most original, completely overlooking the fact that every generation did do something better than the others at the time.
In order to encourage reflection on these games I'm opening a discussion on a couple of points. You can be biased, but please take the time to consider and compare every generation against each other, and not just your favorite.
1. List the generations from favorite to most hated. Generation 6 can be included as well if you just love it already.
2. List the strengths and/or weaknesses of every generation in your opinion. Anything can be included: Sprite, model, graphics quality; Game play and mechanics; Competitive play quality; Wi-fi and connectivity; Music and Soundtrack, quality wise or melody wise; Storyline and characters; Anime; or anything else you can think of.
Gen 5: 150 entirely new (well some copycats) Pokes. Best gameplay mechanics, battle mechanics, and battle animations. I absolutely thought Team Plasma was hands down the best Super Villain team: (Colress, N, Ghetsis). Team Plasma was better in Black and White though; in BW2 they were more mechanical. The storyline did get you more immersed than in past generations, even the gym leaders were more active. It had the best music, quality wise. There was much attention to detail: levitating and flying Pokemon not hitting the ground upon being sent out for example. HMs were optional (except for Surf I think, correct me if I'm wrong!) and by that I mean you didn't have to use them to get through the game, which I loved. TMs could be used infinitely. The Pokemon were bad though I'll admit. The artwork is something to be frowned at and is this Gen's biggest flaw. Nevertheless there were still some good Pokemon additions, and competitively, the pokes wipe the floor (stat wise) with those of past Gens. I stopped watching the anime … enough said. There wasn't much to do post-game. The gym leaders and E4 in this game were the weakest of any Gen (on Easy Mode). It was great that they gave the option of 3 difficulty modes but the way it was implemented was less than stellar. This Gen also capitalizes on the successes of Gen 4.
This was where it all started. Best sprites and originality of Pokemon, best gym leader music (melody wise, not quality wise), best anime season, there was quite a bit to do post-game (Sevii Islands). I spent a good chunk of time hacking this generation so I really got to understand the mechanics which were good. I owned Leaf Green which was the first Pokemon game that I ever played, I loved it. This is a game I could definitely go back and play again - only for nostalgic reasons though, it'd irk me to see my Pokes not move. I didn't like how physical or special characteristics of moves were attributed to type; there were only 50 TMs which could only be used only once; HMs were mandatory for parts of the game; connectivity was a hassle or non-existent. The storyline was relatively mechanical and didn't get you too immersed in it.
Gen 2: Capitalized on Gen 1's successes, 16 badges and 2 regions (there was so much to do post-game), Day/Night system, also a great anime season, great music, great sprites, etc. I actually only played Soul Silver so I wouldn't be the best judge of Crystal, Gold and SIlver. The gym leaders and Elite 4 in this game were rather weak (excluding Miltank) The same flaws of Gen 1 apply here.
Gen 3: Greatest difficulty in gym leaders (though some will disagree with me on this. Almost every gym leader there was tough except Watson: Roxanne's Nosepass, That annoying Makuhita, Torkoal's surprisingly good defences, Slaking ... must I say more?, Altaria, Tate and Liza's Claydol-Xatu-Eathquake combo, Kindra was just annoying with Double Team.), Secret Bases, Pokemon Contests, and some great Pokemon additions (Milotic, Salamance, Aggron, Flygon, etc.), and good sountrack with the trumpets <3 Sadly there was no Day/Night System, The Pokemon levels were low, and grinding was the most annoying in this Gen. There was little to do post-game. The flaws of Gen 1 apply here to some extent. Emerald was the second Pokemon game I ever played, (actually I alternated between Leaf Green and Emerald at the time) and I didn't hesitate to jump ship to Leaf Green instead because of difficulty.
Gen 4: Relatively amazing graphics (the back sprites were better than BW1 in terms of pixellation), decent Pokemon additions, attention to detail on moves (physical, Special, Other), The Battle frontier, a decent amount to do post-game, competitive play and connectivity was ushered into a new dimension. The gym leaders were rather weak, and the Pokemon designs got less and less original.
I don't know how to rate Gen 6 already but the way things are going, it will mimic the artistic flaws of Gen 5, and capitalize on the gameplay mechanics and connectivity based successes of Gens 4 and 5.