sooo... I was wondering what items each person gives, for example, the last time I did Cinthia her weekend quests I received a and I had NO idea that item existed... so now I really wonder what other items they give out :p

is there somewhere a list??

There are only a few quests that give out extra items; it was a system they started bringing in for all quests until all the extra items devalued very quickly and they brought in quest points shortly after. Now these items are only randomly awarded if that quest is WSQ.

I don't know of any full list: a list of quest prizes on Subetalodge does list them all, but also includes wizard tokens and Quentin quest prizes. It takes some poking around but you can assemble a list of prizes for each quest type: these are the possible extra prizes Malaria gives.