Complete Monster: Arkady Svidrigailov. This guy began with raping and killing a 13-year old girl and didn't get any better. For the Evulz he had Driven to Suicide a faithful servant, killed his caring wife, molested and possibly tried to rape Dunya, and God knows what other atrocities he committed. A crazy, sociopathic nutjob who truly beleives that Evil Feels Good, Svidrigailov could be easily considered the most inhumane and repulsive character of the novel.
Seinfeld Is Unfunny: Rodya is a college dropout with mental issues, who thinks saving his sister from sexual abuse gives him an excuse to kill someone. Yes, I just described 50% of all Cold Case episodes.
Tearjerker: Raskolnikov's dream about a poor old mare getting beaten to death. Which is also mad Squicky.
The Woobie: The prostitute Sonya, who was forced into it by her family. Raskolnikov and (arguably) Semyon Zakharovich Marmeladov are of the jerkass variety.