couple of films i feel are pretty damn classic (or will be)...

requiem for a dream (modern classic)
in the mood for love (international classic, classic love story)
pulp fiction (modern classic)
lost in translation (classic love story)
eyes wide shut (people shit on kubrick for this, but fuck 'em)
irreversible (devastating, completely unique, compelling)
la dolce vita (the last scene is incredible)
battle royale (see it for the controversy)