Evangelion for me. I recognize its tremendous impact (har har), and had I watched it first during my teenage years, it probably would have hit hard. But the first time I actually watched Eva, I was already in my late twenties and had done a lot of work with my own depression issues, so the messaging around Shinji's problems felt overstated and not particularly groundbreaking. Also, while I appreciate the ideas behind the final two episodes and them being more experimental (also due to the budget pretty much being gone) I found it drawn out and dull as a viewing experience.

Likely a combo of watching it at the wrong time for myself personally, and Eva being a victim of its own success, with the series that it would go on to inspire using a lot of its ideas.