Elwes is definitely back for Saw 7,it was announced by the production company.There was meant to be 8 movies,but the last one didn't do so well (at the box office) so they are wrapping the story up this year.
As for my top 5 - that changes quite often,but at the moment:
1) A Nightmare on Elm Street - not the masterpiece that some say it is,but highly effective if naturally dated and weakened by the sequels.Great atmosphere,extremely imaginative and featuring numerous disturbing set pieces.
The awful remake rekindled my love of this film.
2) Texas Chainsaw Massacre - Original,funny,relentless and due to the budget has realism and a style of it's own.
3) Confessions of a Serial Killer - Decent little Henry Portrait of Serial Killer type movie that I really like for some reason.
4) Possession - Watched it very recently,and what can I say - I love trashy,cheap made for tv horror of the 1970's!
5) Paranormal Activity - Basic,not very original and perhaps too slow.But it worked on me.