Some films I've watched recently...
I've picked out ones I think you'll like from what you said in the OP.
-Lucky Number Slevin [Thriller]- Watched this last night and it was brilliant. Very slick and stylish, great cinematography and plot. Highly recommended. [8/10]
-Wolf Creek [Horror] - Similar theme as Hostel, but this low-budget Australian film is definitely worth a look at. Fairly gruesome in some parts although the film relies mostly on tension rather than visually imagery. If you haven't seen Hostel, watch that too. [7.5/10]
-Running Scared [Thriller/Action] - Much like Lucky Number Slevin, it's fast-paced and slick. Only this has some more disturbing scenes and is much more violent. [8.5/10]
-Crash [Thriller/Drama/Crime] - Absolutely outstanding. Almost had me in tears. It should appeal to everyone because of the diversity in the scenes and characters. Ludacris (the rapper) did a good job at acting too. ( [9.5/10]
-Man On Fire [Thriller/Action] - Tarantino called this the "Godfather of revenge movies" and I see why. The montage editing gives it a unique appearance and it's an awesome film. Fantastic acting from Washington and the little girl. [8/10]
Finally, I recently watched a French film called Irreversible. This is one of the most disturbing films I've ever seen. It is extremely graphic, conveying imagery of rape, homosexual activities and violence in prolific detail. However, artistically it's impressive. The camera changes about 5 or 6 times in the entire film. It's as if the entire film was made by one man with a camera, because the film is raw. No sets, no lighting, no crew etc etc.
I honestly think all young women should watch this because it's a good way of educating them about the sick, disturbed people who lurk around at night.