What game would you reccomend to someone who's only played Pokemon?

Again

Depends on the person

Mystery dungeon fans would probably mystery dungeon

This is a far broader topic than my question, as it concerned only one series, not all of gaming. In this case I think it depends much more on them as a person.

Another somewhat surprising issue is that a number of Pokémon fans do not like turn-based games, or video games in general. There is a sizable population of people for whom Pokémon is the one game they touch, the only exception and consider everything else is dorky and unplayable.

But given that they have asked specifically about other games in this scenario, and assuming they actually like Pokémon and particularly the turn-based JRPG aspect, I might recommend series like Dragon Quest, Final Fantasy and Shin Megami Tensei.

I might also suggest they branch out and try western turn-based RPGs, but they tend to skew much older or indie because at some point the western AAA space decided gamers hate turn-based games and every game needs the pretense of a Hollywood action movie. Then they are shocked when something like Baldur's Gate 3 comes along and is hugely popular.

If they were focused on the monsters aspect, I might point to series like Digimon, Shin Megami Tensei or Palworld.

From there, it really depends on their individual tastes. Fictional genres they like, such as fantasy or sci-fi, might guide my recommendations. If there is a sport they like, I might recommend those games.

Of course, one could always provide a list of your own favourite games, but in my case I think they are more niché or not a good introduction for someone new to a genre. I am not likely to say to someone whose only gaming experience is Pokémon, "oh, yeah, you should jump into Dark Souls" unless I have good reason to believe they would enjoy the experience.

Generally nostalgia. They played Pokémon as a kid, they like Pokémon, they buy every new game and give it a pass on all the conventions of a turn-based RPG that lead them to declare that other such games are boring and unplayable.

It is not uncommon to see people lamenting the fact that Pokémon is a turn-based RPG; things like the exp share exist to mitigate the effect those elements have on the game to placate such people, and as a lover of turn-based RPGs, it makes me afraid that Pokémon will one day become an action RPG specifically to appeal to the dreaded "wider audience" so many other franchises have utterly desteoyed themselves over pursuing.

I think Z-A was an experiment in that direction.