I played every mainline AC game so I will write lists about the pros/cons of each one. It’s a *personal* list about what I enjoyed and disliked, just for fun! This isn’t objective.

:: Game Cube ::

💚 Love.

• 10/10 Villager dialogue, lots of it is interactive on top
• Flowers don’t wit
• Music gives it an unique feeling very different from next entries
• Focused on single player, it makes sure there are TONS of small activities and events to not bore you.
• Monthly lottery
• Can write a diary
• Nook builds you a statue when you finish paying your loan
• Can put signs outside and decorate your door with custom designs
• Villagers play with balls outside and it’s so cute
• Can enter villagers’ houses while they’re outside
• You get playable NES games for free
• The pond is lovely
• You can visit the GBA island and meet new villagers there

💢 Disike

• You can’t upgrade to the final Nook shop without playing with someone else
• A handful events only happen at one specific hour
• Fixed camera is kinda annoying
• Villagers move out pretty randomly
• No hairstyles, you are forced to wear a gnome hat
• No storage
• Sometimes villagers rob you lmao
• Trees difficulty visibility sometimes

Overall, ACGC is the best game if you don’t have anyone to play AC with, when I say there are TONS of events, I mean A TON. Big ones (Easter), small/made-up ones (sports day) and small activities (lighting up the lighthouse).

Plus there are lots of little things that make the atmosphere of this game unique, and even though there are some things I find annoying (no storage….) the positives totally beat them, the villager dialogue alone is gold and you won’t get tired of it.
 

:: Wild Wolrd ::

💚 Love

• Its pixelated 3D model graphics are bad in a charming way
• Again, villager dialogue is gold
• The made-up events are fun
• Bulletin board gets funny monthly/weekly messages
• UFO is easier to shot
• Collecting villager pics is a huge deal, both for you and for the villagers (they remember it!)
• The flea market!!
• No monkey villagers (unless you're visinting a Nintendo zone in 2006)
• Villager house exeriors are my favorite in the entire series
• Bottle messages
• Making constelations (and making them appear in others' towns and viceversa)

💢 Dislike

• Not much to do outside decorating, though events are pretty contant.
• Making designs is kinda hard due to the small screen & no zoom
• Can’t unlock hairstyles & the last Nook upgrade without someone else
• Only 8 villagers
• Despite monkeys being an exclusive species, gorillas are still here 😔
• All players have to share a single house

While I’m aware it’s not objectively the best one, I consider ACWW my favorite AC game! It looks so bad I can’t get enough of it, and despite the ~13 years I have been playing it, I keep finding new dialogue here and there.
I find it very fun despite not having as much to do as other games, the villager dialogue most likely helps.

:: City Folk ::

💚 Love

• The city, of course. Gracie Gracie, house expositions, Kicks and theatrer added so much life to the game.
• Return of the real-life events
• Better clothes customization
• Can unlock all of Nook upgrades by yourself
• You get a little flag for your home when you pay off all your loan
• You can build a fountain (with its own NPC!) and a lighthouse/windmill for the town
• Bottle messages & constelations are back

💢 Dislike

• Town is as big as a country, so it ends up feeling pretty barren often due to all houses being pretty apart from each other and flowers/trees being the only decoration.
• Just ACWW without the charming graphics
• No villagers pics :(
• When you talk to a villager, they say dialogue A & after that, they keep repeating dialogue B (a response to A) until you reset it via entering/exiting a building.
• Grass dies if you walk around town too much
• House only have 3 rooms (main, upstairs and basement)
• Made-up events are gone in favor of real-life ones
• UFO are a pain to shot, blink and you miss them

Despite ACWW being my first game, due to some circumstances I ended up playing ACCF for a way longer time instead, so I consider it my childhood AC game and the one I have the most memories of.

But to be honest… I don’t consider the game that good, it improved stuff over ACWW and yet I find it more lifeless. Haven’t touched it ever since I deleted my original town aeons ago despite my numerous attempts.

:: New Leaf ::

💚 Love

• Graphics are polished but still pixelated, best of both worlds.
• Can put a certain set of items outside
• Probably the game with the most amount of furniture/clothes thanks to the Amiibo update
• Can change the color of some furniture
• 360º camera view inside rooms
• Museum rooms you can decorate
• All emotions are available to use (as opposed to ACWW/CF where you only could use/save 4 at a time)
• Dialogue textbox is black and it looks cool
• Added more villager species & personalities
• Free access to the Dream Suite & others’ QR designs
• You can place your house anywhere you like
• Villagers won’t put their houses on top of designs
• Swimming and diving
• The island is back & has minigames you can play with others and buy exclusive furniture
• Nice minigames inside the 3DS and Wii U furniture
• Designs aren’t limited to pre-made palettes anymore.
• Added shorts, socks and shoes, along with long, short and sleeveless tops
• Added bushes and new fruit
• That place where it saves the houses of people you stretpassed & can buy stuff from them
• For 3000 bells, flowers wont witter ever again and you won't see a single weed
• The bean box :)
• Perfect fruit

💢 Dislike

• Placing stuff outside is an ass sometimes
• A good chunk of furniture is pay-walled thanks to Amiibo
• Can’t place stuff at the beach
• Town can get crowed easily (this is both a good & bad point imo) due to its small size & all the furniture and buildings
• Made-up events are gone for good, including the flea market
• Barely had any Wi-Fi/collab items (zodiac set + 3 or 4 items more), at least in EU
• Japan got all the cool items, both event & Wi-Fi/collab ones
• Villager pictures are back, but they’re nothing more than a piece of furniture more. All the importance villagers gave them in ACWW is gone, they give it to you as a normal reward.
• Not too many events, so you may get bored.
• Fixed town maps & no double rivers anymore.

I think ACNL is objectively the best/most rounded-up AC game, definitely the one I always tell people to play as their first AC game. It was complete already in release, but the Amiibo update made it even better (despite the paywall). The online comunity was also super fun, I miss it...

I said ACWW was my favorite game, but it’s very very close to ACNL. The dialogue in this one is way more stale, but still has a nice variety. I got 1.6k hours on it and still pick it up from time to time; I recently hacked itand it even added more fun to it thanks to removing the paywalls & being able to do whatever I want.

:: New Horizons ::

💚 Love

• Prettiest graphics ever, I can spent hours spinning the bread basket 3D model
• New furniture sets and tons of food.
• Interactive furniture and wall/floors.
• Remodel the entire town
• Can place anything outside
• You can move buildings
• Island made it easier to find villagers you like
• Villagers interact with the furniture outside and it’s the most adorable thing ever
• Items aren’t county-exclusive anymore
• Pretty much any furniture can be customised
• You can change your mouth and nose now, along with designs on your face
• New design stuff to hold, like little flags.
• Camera, both to take pics and to change the angle, is WAY better
• The Raymond craze was funny ngl
• Lots of design slots
• You can invite your villagers to drink coffee if you got their Amiibo card

💢Hate

• Runs at 10fps
• Removed 70% of previous furniture sets and re-designed the ones they kept (and for the most part, made them more minimalistic)
• Everything is so pretty it’s sterile at times.
• Crazy Nook prices, the 2k laptop now costs you 80k bells.
• Barely any villager dialogue (2nd day and I was already getting repeated lines) and it’s stale for the most part
• Barely anything to do if you aren’t into decorating
• Events are ridiculously easy
• Crafting is troublesome imo
• Design slots are shared with all players
• No Nook upgrades and you will get the same 10 furniture every day on repeat.
• Almost impossible to collect furniture unless you play with others
• You have to pay to scan design QRs, visit the dream suite and play with others online
• Removed ACNL’s new fruit, and the normal ones are impossible to get unless you play with others (on your own, you’re only able to get 2 kind of fruits)
• Added more design kinds but removed some of them. For example, you can’t make a short dress with long sleeves, you have  to either make a balloon dress or a wedding dress
• Clothing designs have premade textures instead of being a blank canvas, which makes difficult to make certain clothes (a shirt with short sleeves will always have a collar, buttons and folds regardless of what you want to make)
• Anti-aliasing makes pixel art and clothes look weird
• Villagers never ask for requests
• Seasonal recipes are only found in balloons and they almost never appear. And when they do, it’s not guaranteed they will drop a recipe.
• Tools break. Even the gold ones.
• Writting letters is troublesome (you have to talk & confirm various dialogues with the birds to send each letter)
• Removed a ton of NPC, even old ones (gracie..)

I will be honest, I hate ACNH. It did so many things good, but the bad ones beat the positive. Since I bought it in 2020 I only played 200 hours when with every other entry I easily get to the 700 hours in that same time frame. And it was during lockdown, mind you. It bored me so much I picked up NL/WW again instead.

I would say ACNH is only good if what you’re looking for is a cute decorating game, but not even that would be true because the game REFUSES to give you new furniture. You will have to either pay $20 to play the HHD version or pay for online to trade with others. On your own, you can  barely get anything.
It could've been one of the best AC games, but they wasted the oportunity :(