I think that Sir PewDiePie should try one of these games,i played some and they're scary and challenging...
WARNING!!! SPOILERS!!!
Resident Evil 1
Youtube gameplay: youtube.com/watch?v=zo7XyBFHtAs
Resident Evil 2
Link: youtube.com/watch?v=psocOySFePA
Resident Evil 3
Link: youtube.com/watch?v=_BeYlilQUWY
Now to continue the Silent Hill saga...
Silent Hill 2 (one of my personal favourites & one of the best games i ever played)
Link: youtube.com/watch?v=B8kVqUCo3Y8
Now for the newer ones...
Devil May Cry 3
Link: youtube.com/watch?v=vi0s_UDWk6I
Devil May Cry 4
Link: youtube.com/watch?v=aXF5J5bBBmQ&feature=relmfu
Anyone that knows a good game,please write it in the post,maybe i'll try it too