For PS & DS, I would go for some of GMAT Club's compilation(collection) first, such as 1000 Series. Then I think questions from reputable prep companies, such as Manhattan (
MGMAT), Veritas Prep, Kaplan, Princeton Review, etc, should have decent quality. For these two questions types, non-official questions can still be beneficial if you need more practice.
For RC & CR, I personally would stick to official questions only, as it's difficult for any prep company to replicate the GMAT-like questions. For official questions, you are left with LSAT questions, which are high quality but generally a bit more difficult than their GMAT counterparts.
For IR questions (DI excluding DS), since the supply of official questions is quite limited, one may need to "settle for" non-official questions. Again, questions from reputable prep providers mentioned above should be of decent quality, though might not feel 100% authentic. So it's really a trade-off between having more questions to practice vs. the quality of the questions. Here is a post where the OP used
Forum Quiz to produce large volume of question sets for his/her DI practice, which imho is quite a creative way to utilize
Forum Quiz:
Forum Quiz helped to improve DI scoreJust my two cents. I'm also curious to see if anyone else has found some hidden gems in terms of question source.
Paras98
Given we can't choose OG questions any longer, can someone pls suggest what all sources should we consider for each section while attempting
Forum quiz questions