"Seven" was a thrilling and suspenseful crime crescendo
"A Simple Plan" was a smart almost indie-thriller. Not quite the mystery that Mystic River was or anything, but very character based. Haven't seen it in a good while, should try pick it up.
"Memento" really is the front runner though.
Two good mystery thrillers..
In the Valley of Elah...
Was going to recommend Lone Star. One of the best films of the 90's
The original Dutch/French "The Vanishing"
The terrifying French "Them"
The original "The Day of the Jackal"
List threads are against charter and this one has run its course. Locked.