[LaMe1337]

Uh, since you've seen a lot, could name some you liked as well?

I liked:
autopsy of Jane Doe
exorcism of Emily rose
deliver us from evil
dead silence
Eden lake

you may have seen them, but those are the only that came to my head.

Also one worth watching is "El laberinto del fauno", it's Spanish though. Eventually Los otros (the others), it's somehow in English (can be found in Spanish too), but I guess you saw that.
Oculus - welp...not that good, but decent.

Next one is not for everybody, but I love that kind of british humour: RocknRolla (you either love it or hate it), In Bruges (same here)
grand hotel Budapest
21 jump street
22 jump street. (last two are bit of mainstream though)

Well, I hope you haven't seen at least one and eventually you will like it if you see some of them. It's also hard to tell what do you consider mainstream as it differs from country to country and with comedy taste it's hard as people have different kind of humor.