We get money rewards so that we can spend them, hence I don't shy myself from not finishing those money.
Hyper Potion, Full Restore, Revive, Full Heal, PP Up, Protein, Carbos, etc. are the items which I had used consistently. I always keep their stock over 20, as soon as I had got enough money 💰.
In older generations, there used to be items like Power Bracers, Power Anklet, etc. Which I use when I train certain Pokémon in order to mitigate their bad nature and had done max-min method for them. I don't know whether these things exist or not nowadays.
There used to be something called Dowsing Machine, Devon Scope, and things like these which were handy in their own regard.
Exp Share and Lucky Egg were my favorite when leveling up my Pokémon. The Pokémon Company made leveling Pokémon very easy due to Exp All. Not a fan of it as people are not aware of how hard it could be to make Pokémon stronger.
Old Rod was bad, but at least it gave Magikarp and Feebas, hence used it for while! But never felt the need of using good and super rod, because by that time I had already got some better Pokémon hence didn't bothered to waste my time there.
Boosting battle items like Choice Band, Choice Scarf, Assault Vest, etc. are good but I never really felt the need of it as in-game battles are too easy to be making use of those strong held items. Setup sweeping is single simple method to clear the battles. Hence HP restoring things like Leftovers and super-effective attack boosting item like Expert Belt are the one which I had used.
Apart from these, items like Mega stone, Z-stone, Griseous Orb, etc are used by me because these are things which are important in their particular games.