Personally I found Dog Soldiers the best of Marshall's outputs - gotta love a humour level that's on par with The Evil Dead 2: Dead By Dawn and The Texas Chainsaw Massacre 2.
It's gained a cult following so it's not been totally lost.
Personally I also found the following underrated aswell:
Undead
Clive Barker's Nightbreed
The Blind Dead Series
The Birds
Shadow of the Vampire
Zombie Diaries
Nightmare City
The Crazies
Hellraiser 2 - Much prefer this to the first film
The Witchfinder General
Children Shouldn't Play With Dead Things
Dracula 2000/2001
Dead Set - not a movie but still lost on E4's typical audience