Reservoir Dogs has a simple (read: low budget) plot. A gang of criminals are planning a diamond store heist. Planted among them is a police officer who notifies his colleagues about the gangsters' plans. When the criminals try to rob the store, there's a gunfight in which some of gangsters die and the cop is wounded. The survivors of the gunfight rendezvous in an abandoned warehouse, and accuse each other of being the plant. The conversations in the warehouse make up most of this movie.
Needless to say, Reservoir Dogs also has an extremely low budget setting. Most of the action takes place in the afore-mentioned warehouse. In stark contrast, a bit of it takes place on a terrace on a bright and sunny day. In a lesser degree of contrast, some of it takes place in restuarants and dimly-lit bars. Quentin Tarantino, now famous for messing around the chronological order of a movie, switches between these spots as he goes through the rather simple plot. The result is extremely effective: the violence, which is fairly routine in movies these days, is terrifying.
In retrospect, Tarantino's first film remains his most effective one. While Pulp Fiction was excellent, it was too long which resulted in certain parts having a bit of monotony (Reservoir Dogs is almost half the length of Pulp Fiction). In Pulp Fiction, the characters showed signs of emotion. Here, the characters are all bleak, just like their surroundings. There is a slightly greater amount of violence, but the emotionlessness of the gangsters is what makes this movie so powerful. That people can kill so casually, without feelings, is frightening, and the cinematography in this movie brings that aspect out brilliantly.