Pokemon... Where to start (Nintendo DS)

[MysteryLemon]

My daughter has a birthday coming up. She's declared she would like a Pokemon game to play on her 2DS.

I've done a bit of googling for 2ds, 3ds and older DS Pokemon games and there is simply too big a range to pick from. X, Y, Sun, Moon, Platinum, Ruby etc. I haven't got a fking clue.

What's the difference between them? Will any be better than the others for a beginner? She's never played a Pokemon game but she loves the cartoons. Seems like Sun and Moon for the 3ds are the newest ones? They are the most expensive anyway (£40 in most places) but I would rather go for something older and cheaper as for all I know, she might not like the games so don't want to waste £40, unless the newer games have something worth spending the extra on?

Any help appreciated haha. Pokemon games are a minefield...