Arachnophobia (1990) 
Veering from my list already by day 2
I watched this 1990 'PG Horror' which I've not seen since I went to the cinema as a 13 year old, and scared the pants off myself!
Tonally a bit all over the place for the first 2 acts but actually scary for the final 30 minutes when the spiders start killing everyone in sight! I was literally sat on the edge of my bed and I felt them crawling all over me. I'm going to continue the horror now with episode one of
The Apprentice on BBC1