Wood-
Thunderhawks second drop(not the backside of the hop after the first drop) is one of the most intense drops on any ride, in my opinion. Downward curve through the rides structure. Great drop.
Jack Rabbit was the first coaster I ever rode. So add the nostalgia to the double dip and it's easily one of my favorites.
Those and the Thunderbolts last drop stand out against the rest for me. I just love the charm of a thrill that's decades upon decades old and still holds up against the modern rides.
Steel-
Millenium Force, obviously.
Apollo's Chariot has five drops that would count as some of my favorites but two really stand out for me. The first drop and the third.
Phantoms Revenges second.