I don't think anything is going to top his role as Neo in the OG Matrix for me, even though his performance is a bit wooden at times. There is something ingrained in the deepest recesses of my being, likely from watching the movie hundreds of times over the years, about the casual, indifferent, I'm-in-over-my-head way he delivers his lines. I think he was the absolute perfect fit for this role and worked extremely well alongside Laurence Fishburne's Morpheus.
The only part of this role that fell flat for me is his romance with Trinity, but that was never a highlight of the movie for me anyway, so I let it slide.
What is your favorite Keanu role?