Some great choices posted by everyone so far. I'd have to say that Enemy of the State might be the best Bruckheimer movie. I always find myself watching it on cable on a weekend afternoon and still enjoy it.
Peter Bogdanovich's Targets (1968), about a Vietnam vet who goes on a shooting rampage with a sniper rifle
John Carpenter's Assault On Precinct 13
The Parallax View, while not as good as Three Days of the Condor, is a pretty good thriller.
Rolling Thunder
The Killing of a Chinese Bookie, not a thriller but a good crime movie
The Driver
I also love Night Moves.
One movie that is not a thriller but a classic cable TV movie to watch that I still associate with these kind of 1970s movies is Papilllion, the movie with Dustin Hoffman & Steve McQueen imprisoned on an island.