Your favorite medical horror film.
I have been a fan of this film since the mid-eighties. I was too young to see it in the theater, but luckily my family had cable, and we had three of the four movie channels (yes, kids... I'm over 30 and we only had four premium mainstream movie channels back then), so I was fortunate enough to watch a lot of unedited horror movies. Re-Animator wasn't on often, but I made it a point to either stay up and watch it or set the VCR timer and put a piece of transparent tape over the punched out tab to record over some other movie that I no longer wanted to keep.
How many did I lose after that last sentence? A bunch? Thought so.
The coolest thing about this film is that it is based off of a long out of print story by H. P. Lovecraft. The story could have been comic farce if put into the wrong hands. Jeffrey Combs plays Herbert West superbly and without his performance, this might be a staple on MST3K.
The film concerns itself with West tinkering with a serum to re-animate the dead. He revives his professor, but gives him too large of a dosage and unexpected side-effects occur. When he furthers his studies, West runs into Dr. Carl Hill, who stole his professor's theory on brain death and therefore finds an enemy.
The rest of the movie finds West being screwed over by his new enemy and testing the serum secretly. The most memorable scene happens after Hill's decapitation and re-animation. This movie is definitely something that every self respecting horror buff needs to see.