From the late 50’s, my favorite low-budget, really bad creature feature, that I’ve always loved anyway:
The Beast From Haunted Cave
Carpenter’s Thing, Forbidden Planet, King Kong, Godzilla, Nightmare on Elm Street. Candyman, for some reason.
I have a soft spot for the *premise *of Mimic, but the execution was not so good.
THEM!–single best “giant radioactive whatever” flic made in America in the Atomic 50s.
Good solid script, excellent directing & camera work, dynamite cast!
My favorite will always be Abbott and Costello Meet Frankenstein. What a great concept. Classic comedy team meets the classic Universal monsters, with the real stars (Bela Lugosi as Dracula and Lon Chaney Jr.as the Wolfman) playing their roles (gotta love the old studio system.) That would never happen today.
I also have a soft spot for the Godzilla/Mothra/other assorted monster movies. Loved those as a kid.
But for best, I’d say Alien.
Re: Abbott and Costello
Sandra? Junior? Sandra ? Junior?..I love that movie. Great quote from that movie:
“She has so much bridgework,you have to pay a toll when you kiss her.”
The Thing (original)
The Mummy (Karloff)
Dracula
Jeepers Creepers(both ) am I the only fan?
The Werewolf (Lon Chaney version)
Jaws
Them (best of the giant mutants)
Hound of the Baskervilles
America werewolf in London
Night of the Living dead
Let the Right One In
Horror of Dracula
Bride of Frankenstein
Alien
Then of course there are a shitload of great Flying Saucer movies.
Invasion of the Body Snatchers ( original)
When Worlds Collide
Aliens
War of the Worlds (original)
etcetera
It’s not the best of all time, but I’m surprised Cloverfield hasn’t got a mention.
Best monster movie by me (at this instant) is Shadow of the Vampire.
One of the stranger monsters: The Monolith Monsters.
Killer rocks from space. Seriously.
Actually, not a bad movie and better than most B-grade movies of the era.
The science and solution were actually plausible.
One of my all-time favorites, the immortal CALTIKI.
Lots of great suggestions on this thread. But I wanted to jump in to say no, you are *not *the only fan of Jeepers Creepers. I thought both of them were fresh and original, funny and scary at the same time…TRM
Nobody’s mentioned Terminator?
“That terminator is out there. It can’t be bargained with. It can’t be reasoned with. It doesn’t feel pity, remorse or fear. And it absolutely will not stop, ever, until you are dead.”
And then it proceeds to live up to that line. Now, THAT’s a monster. The sequels, not so much, but this is a monster movie.
Good one. A terrific “bad” movie. I recently acquired a copy of the DVD (a poor quality video dub from god knows where), and “the scenes” that you and I are both thinking of right this moment are every bit as horrifying and creepy today as they were in '59.
“Caltiki” and “Beast From Haunted Cave” are the two that have stayed with me from childhood.
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That’s a great link to the film, btw.
I’m a big fan of the classic '30s monster movies, especially Universal’s. Those, and many of my other favorites, have already been named.
So… I’'l throw in the low-budget Ginger Snaps, a werewolf (as opposed to wolfman) movie from Canada. Extremely well made movie, despite the budget, or lack of same.
Deep Rising is a fun, cheesy B-movie.
Lake Placid is also fun, with a terrific cast.
Dragonslayer is still the best dragon movie around, but I do have a fondness for Reign of Fire.
The Edge is pretty thrilling. It’s like Jaws, but with a bear.
I stand corrected. 
Count me among the fans. The Creeper is a cool–and very scary, IMO–monster.
Lot of good choices here. My favourite, like many others’, is the Alien.
Personally, although I’m a big fan of horror movies, monsters have never really turned me on. I’ve always preferred ghost stories or psychological suspense thrillers where the horror is internalized rather than stemming from an external boogieman.
That said, I’ll always remain traumatized by the Zuni Fetish Doll. That movie made one hell of an imprint on me as a 10 year old kid.
The Thing from Another World Was years before I ever saw the beginning of that film. Always tuned in when it had been on for 30 minutes.
A lot of my favorites hqave been mentioned, but I’ll list them again. Also, a lot of films listed aren’t, to my mind, “Monster Films”. Forbidden Planet? Hound of the Baskervilles? You can make a case for them, but it’s pretty far from what my definition of “Mopnster Movies” would be
King Kong – both the 1933 original and Jackson’s version
The Fly – both versions
Them! (don’t forget the exclamation point!)
The Beast from 20,000 Fathoms – The UR 1950s monster movie. It was the very first “monster” movie of the 1950s that featured the iconic Giant Beast on the Rampage, driving people through the city streets in Terror, and it had all the cliches – the Handsome Young Scientist, the Beautiful Assistant/Love Interest, the Giant Creature awakemned by Atomic Blasts, and We Only Have One Shot to Kill It – but they had never been used before, so they weren’t cliches. Also, Ray Harryhausen, lacjing the Big Bucks they had for King Kong and other earlier films, had to invent an entirely new process – his Dynamation/Dynarama/“Reality Sandwich” – to enable him to put his animated monsters in with real people and settings. Overall a revolutionary film. And still one of the best, if not THE Best.
Kronos – it’s brain-dead, but it’s artistically gorgeous. Special effects by the same guys who made Forbidden Planet. You’d never believe a big rectangular box could look so good and complex on-screen. Made in black and white, but in wide screen. The titular Kronos is a giant robot from outer space who starts marching across Southern California and Mexico on its weird stumping three legs (and one rotating one) stealing power from generating plants. Its death throes at the end are worth sitting through the rest of the film for. And it’s such an off-the-wall concept that it stands out against the rubberoid monsters of the 1950s. It was also a big influence on Brad Bird – I could tell the director of The Iron Giant had seen the film. And there are echoes of it in The Incredibles, too.
The Monolith Monsters – another oddball, among the giant insects and dinosaurs of the 50s. The titular “monster” isn’t even alive or evil – it’s a crystal from outer space that replicates in the presence of water, and threatens to destroy a town. Weird and interesting.
Godzilla – it’s an imitation of Beast from 20,000 Fathoms, but its inspiration is really pretty touching – it almost certainly owes a great deal to the real-life tragedy of the Fukuryu Maru and its aftermath – a real-life tragedy of the atomic age. And it doesn’t suffer from the puerility of the later godzilla movies. It’s certainly become a world-wide icon.
The Blob – I have to admire the low-budget but high quality of the film. Imaginatively made. The 1988 remake is pretty good, too.
the Thing – both versions, for different reasons.
Tremors and, to a lesser degree, the first two sequels, which managed to be interesting and imaginative without being repetitios.
The Host
The Lost World (1925) – if only for the rampaging brontosaurus in London – the first time we had a Monster On The Loose in a City in a live film.
The Giant Pet – as far as I know, Winsor McKay’s circa 1921 cartoon is the first cinematic expression of the Monster On The Loose in the city. They even try to shoot it down from biplanes!!
Mary Shelley’s Frankenstein (1994), directed by and starring Kenneth Branagh as the good Doctor.
It is very faithful to the original novel, beginning with Victor Frankenstein, deathly ill, being taken aboard an Arctic exploration ship and recounting a fantastic tale of a murderous man-creature. The creature, played by Robert De Niro, is intelligent, cunning, and articulate, contrasted to Boris Karloff’s interpretation of him. Instead of being clumsy and simple-minded, he is a worthy adversary to Frankenstein, first intending to get revenge by killing Frankenstein, then promising to leave humanity alone in exchange for Frankenstein creating a bride for him.
It’s a bit longish at 123 minutes, but if you have read the novel, you will appreciate the faithfulness of this film to the original source. It is worth watching just for De Niro’s performance as the creature. I hesitate at calling him a monster. I found myself developing great sympathy for him as a creature who tried at first to be decent and kind but is warped by people’s treatment of him due to his shocking appearance.