Friday the 13th Part VIII: Jason Takes Manhattan (1989)
http://www.imdb.com/title/tt0097388/?ref_=fn_al_tt_1
Some say this is one of the worst movies of the franchise, but if youre a big fan of Jason V you will watch it anyway. Its kinda goofy (but not even close to Jason X). It was also way less bloody than usually. The actual Manhattan part comes way late in the movie and it is disappointing. They could have made something great out of the "Jason in Manhattan" concept.
The Prowler (1981)
http://www.imdb.com/title/tt0082951/?ref_=fn_al_tt_4
Watched it again some time ago. The movie has really original death scenes and very nice special effects made by Tom Savini. The plot is well written and it had a bit of twist at the end. Basically; GI gets dumbed by hes girfriend and after returning he goes on a rampage. The atmosphere stays cold blooded throughout the movie.
All things combined; a above average slasher and a definite classic.
Edit: the years of the movies.