Topic: How do I choose a Pokemon game?

I’ve only ever played Leafgreen in the past, and I don’t really understand the differences between all the different Pokemon games. There seem to be a bewildering number available on the 3DS alone - X, Y, Sun, Moon, Ultra Sun, Ultra Moon, Omega Ruby, Alpha Sapphire. I want to get one as I enjoyed Leafgreen and the pikachu movie has got me in the mood (maybe I should just get detective pikachu!) for some Pokemon. Can someone help me work out which is the best game I should get?

I think that all 3DS ones are pretty good. I'd say that X/Y or Ultra Sun/Moon are good choises (and if you find any of these discounted price, even better).

Each main-series Pokemon game is released in two versions, which are almost identical but contain a few different Pokemon and sometimes some minor storyline differences. The idea is you just get one of them, then you can trade with your friends to get all the Pokemon if you buy the opposite version to them. So on 3DS, X & Y, Omega Ruby & Alpha Sapphire, Sun & Moon, and Ultra Sun & Ultra Moon are the four pairs of games. OR & AS are remakes of Ruby & Sapphire on the Game Boy Advance, and Ultra Sun/Moon are enhanced versions of Sun/Moon with some new content.
I'd recommend getting X or Y, Omega Ruby or Alpha Sapphire, and Ultra Sun or Ultra Moon. Personally I think the Sun and Moon games and their Ultra versions are the best ones on 3DS, but all three of those pairs of games are worth playing. It doesn't really matter which version of each pair you get.
The 3DS can also play original DS games of course, and there are several excellent Pokemon games on the DS too, so there's a lot of options (I can understand why you were confused!). I hope you enjoy whichever one you end up getting though!

I try to get ALL 3DS Pokemon games as possible because you need BOTH version if you want to get hidden legendary Pokemon from two versions.

Pick them based on the cover.

You don't need to overthink or overspend, just pick something that looks cool to you and let it go from there.

When I was younger I tended to pick a Pokemon game around what my friends were playing. I bought Heart Gold when my best friend bought Soul Silver for example.

If you are largely playing by yourself, just choose one you like the look of the mascot for. The core gameplay will largely be the same: beat the gyms, ruin the bad guys' plans, become champion, enslave your favorite combat animals, etc...

If you are coming off of playing Leaf Green, I would encourage you to play either Pokemon Platinum or one of either Heart Gold or Soul Silver (depending on if you like Ho-Oh or Lugia better). If you still have Leaf Green, and you have a DS, or DS Lite, you'll be able to bring your Pokemon from LG to the DS title after you finish the main story. Then if you enjoy that, you can move onto Black or White and do the same.

You'll be able to bring your Pokemon all the way to Sword and Shield eventually if you play through at least one title in each generation.

Wow this is really helpful, thanks guys! I'm going to go into CeX later and see which ones they have and check their prices compared to new. The Pokemon games never seem to come down much in price even second hand. They're just wildly popular enough people will pay top whack I guess

Oh one more thing - do any of the new 3DS Pokemon games have Squirtle? He's my favourite!

@onemorearrow The Kanto starters, including Squirtle, are in X/Y! Theoretically you could get Squirtle in any of the 3DS games by trading with people online, but X/Y is the only 3DS game where you can get it during the story, as far as I can remember.

I’m sold! I’ll give Y a try!

They seem the most expensive ones though! And maybe I won’t be very good and won’t beat the game; I don’t want to take that risk!

@onemorearrow : In X and Y, you will be able to choose Squirtle fairly early into the game, and it will also come with its mega stone, which will allow it to temporarily transform into Mega Blastoise (that is, once it evolves into Blastoise) in battle.

Let's Go Pikachu and Let's Go Eevee on Switch also allow you to obtain a Squirtle fairly early in the game, or you can catch them in the wild.

play oras, omega ruby and alpha sapphire. as all the gen 1 to gen 6 pokemon are available from these two games. something which will never happen again. then get ultra sun and ultra moon to get all the gen 7 pokemon.

for 3ds u should start with x/y

for ds you can start with diamond/pearl

you dont need to go back to ds in my opinion just start with 3ds