The weirdest movie I've ever seen is Brick. I had no idea what was going on the first time I saw it and the only reason I followed it the second time is because I found the script online and read it while I watched. Although, I must say that I love it for some odd reason and if I had my own computer I probably would've watched it many more times.
Scariest would be Saw. That movie ruined me for horror movies. I used to like them but ever since I saw that movie I just hate them. Part of it is probably because they keep making horror movies more and more disturbing.