Voted for
- Critics' recommendations
- Streamers/YouTube personalities
- Brand/Publisher reputation
- Self-discovery
Like a good content (as you mentioned as well), selection of anything, not only games, cannot be determined only on a single criteria. For me, all of the options you have given are applicable, I have left those which could be of the last resort, though.
Some games definitely fall into the "I don't want to talk about how I found it" category.