It's not even ersatz film noir. It's ersatz Body Heat.
It's beyond me why so many critics put this one on their top-ten lists, or lobbied for its inclusion in the 1994 Oscar race. Think Body Heat (1981) remade with even more comic overtones, and you've got this thin semi-noir nailed to the wall alongside its hapless protagonists. The main difference is that Linda Fiorentino does a delicious job at playing an even bigger bitch than Kathleen Turner's in the earlier film.
The Last Seduction is pretty obviously shot for the small screen, but the real problem is the horribly derivative screenplay, where the biggest surprise is really no surprise at all (John Dahl worked from a far more clever script in his previous Red Rock West [1993]). The first half of the movie is an engaging showcase for cruel one-liners from Fiorentino's Bridget. But once her schtick becomes familiar, the story starts to slow down, and you may start to nod off as The Last Seduction moves inexorably toward a foregone conclusion.
Better you should rent The Grifters (1990), which does a quick and nasty pulp job with a classic Jim Thompson novel, or wait for Kiss of Death (1995), which has no femme fatales at all, but instead uses Nicolas Cage's bruising performance to scare the hell out of you.