I would agree with most about DA:O and Awakening. I consider that DA2 is also a good game, BUT it is really different from DA:O, and I feel like I liked it more after having replayed it later on.
I don’t really like DA:I, and it is only worth it if you also play the endgame DLC, because the base game ending is really underwhelming. And, the game managed to implement everything that I hate about “Open World” games.