T2 has a half dozen or so you could choose from, but that motorcycle chase scene was jaw dropping when I first saw it and it continues to hold up today.
I know James Cameron movies make a boatload of money, so I hesitate to refer to him as "underappreciated," but I don't think he really gets his due as one of the great directors of all-time. I think action is sometimes viewed as a more inconsequential form of film-making, but the ability to create tense, unpredictable actions scenes is rare and Cameron's been doing it for over 30 years.
I'd also be amiss if I didn't give a shout out to late 80s/early 90s John Woo. So many scenes to choose from in his stretch of films that period.