Resident Evil 4 stops being good after the middle of the castle. I don't care how many people go "b-but its supposed to be cheesy!" or "b-but the regenerator tho!". The first half is this tense, stressful cross country trek through some spooky woodlands full of monsters in peoples clothing. When it gets to railcars over lava lakes, hanging dragon cannons and a giant robot dwarf built to destroy the castle around it to scare a trespasser on their way out its not resident evil anymore. Its bowser castle and it only gets dumber from there.
The first half is resident evil at its best, the second half is a direct top of the rollercoaster point to the constant series decline till REmake 2 and 7.