For me, every single armored core game after last raven. Like there is just a lot lost when the series becomes designed around a regular twin stick control setup over the "bad" control scheme that the game was designed around before 4/FA.
Like it just feels much more rewarding to play and beat, and every time I play 4/FA or 6, I almost always want to go back and play 3 and Silent Line again.
I haven't played formula front, and I don't remember when that released.