the early aughts for me.
concept-wise, I think the X-Men were really reinvigorated in a way they hadn’t been for a while. Morrison, Weir, and DeFilippis took the expanded school concept and ran with it. And even though extinction stories have saturated X-Men storytelling for so long, M-Day was one of the OGs and gave us good stories like Decimation, Endangered Species, Supernovas, Quest for Magik, Messiah Complex & War, and Dark Avengers v X-Men.