Ok, since the door of self-indulgence has been allowed to crack open, here're a trio of recommendations representing all segments of my brow.(also they're not necessarily what I consider the best crafted films, but are personal to me):
1) Los Spoorloos (the Vanishing) - do not, I repeat, DO NOT, watch the jeff bridges travesty remake. It's unbelievable what they did to it. Something uniquely disturbing about this film, plus it fits nicely with my obsession with motorway services.
2) Solaris (the Tarkovsky version) - think I've mentioned elsewhere that the director almost deliberately tried to put people off at the beginning with slow sequences, but once you're tuned into the pace of the film, there are some truly transcendent moments (anti-grav: say no more). Plus its philosophical implications 'really make you fink' for ages after seeing. I've heard Will Self say it's his favourite film and it's clear to see why. If you can, see it at the cinema. I rented it twice and couldn't last the distance with distractions present. That makes it sound boring, but by no means is it. You've just got to achieve an almost trance like state, which is a lot easier to do in the cinema. It's well, well worth it - buzzing for days after.
3) Together - this is by Lukas Moodysson, who's better known for crushingly depressing films, however I think this is the happiest film I've seen (something about it) It's my go-to come-down film. The ending never fails to set the widest grin upon my face (and some glistening eyes, depending on how far I'd gone the night before).
Those are 3 I love. If you'd asked me tomorrow I don't doubt not one would be the same, but there you go.
I'll shut up now.