Braindead and Evil Dead Uncut have HUGE quantities of gore, but it's mostly comedic and unrealistic. You'll probably laugh more than you'll cringe or get queasy.
Fulci films were one of my first thoughts as well. Also consider Argento films. You won't have nearly as much organ removal or dismemberment, but the murders and killing ARE extremely graphic and bloody, and the plot is usually more coherent (if that matters?)
Japanese horror was my other primary thought here. The eye gouge scene in Hostel is standard and LOW-key for many of these. Examples include Evil Dead Trap, Machine Girl, and Tokyo Gore Police. If you include late 80's/early 90's anime, things potentially get MUCH bloodier.