Overall I enjoyed all the games in the DA series. DA2 is definitely "the worst," in that it is very poorly made. I also think it's the most unique and interesting game in the series but unfortunately it didn't get the development time it deserved and ended up being very bad overall.
Still, I think the dragon age series is exactly what Larian should look at when constructing their story and characters for Bg3. Origins especially, since the goals this game has set for itself are very similar to the goals of Bg3.
You can argue about the quality of the story and characters of DAO. But you can't ignore the attention to details and coherence of the story.