While I realize this is completely subjective, I feel like I always miss out on some great movies that didn't get the million dollar blockbuster advertising campaign.
Two that specificaly come to mind are:
Into the WhiteNorway, WWII: A group of British and German soldiers find themselves stranded in the wilderness after an aircraft battle. Finding shelter in the same cabin, they realize the only way to survive the winter is to place the rules of war aside.
In Bruges (Seriously watch this movie if you haven't)
Guilt-stricken after a job gone wrong, hitman Ray and his partner await orders from their ruthless boss in Bruges, Belgium, the last place in the world Ray wants to be.