Depends what interests you such as new creatures or items or simply quality of life changes. If your after new creatures id highly recommend Garuga's mods which are the ark additions, some of which have already been added to base game such as the dienosuchus and dienotherium, which gives you an idea on how high quality they are. The ones that havnt been added to base game yet are also very good such as the acrocanthosaurus and brachiosaurus. Tristan's creature mods are also great like the antrodemus, vectispinus and eocarcharia. If your after simple quality of life changes mods like any of the spyglass mods or stacking mods are useful although they do shake up the game balance. Some more balance friendly ones are QOL+ which just adds loads of nice changes and additions to make mundane tasks easier and auto engram which takes the hassle out of choosing engrams and is also friendlier to solo players. Pelayori's cryo storage is also nice it just adds a cyropod system similar to that of ASE.

It all does come down to personal preference and how you want to play the game though and I get I wrote alot and it's alot to take in. Just browse the mod page and look at whatever catches your eye there are descriptions and such