Here is a list of Universal classic horror films, prefaced by release date and current (9/19/10) IMDB rating. Source:
Wikipedia.
1923 7.4
The Hunchback of Notre Dame1925 7.7
The Phantom of the Opera1927 7.3
The Cat and the Canary1928 7.9
The Man Who Laughs1929 7.3 The Last Warning
1929 6.8 The Last Performance
1930 7.0 The Cat Creeps
1931 7.7
Dracula 1931 7.0 Dracula (Spanish version)
1931 8.1
Frankenstein 1932 7.4
The Mummy 1932 6.3
Murders in the Rue Morgue 1932 7.4
The Old Dark House1933 7.8
The Invisible Man 1934 7.3
The Black Cat 1935 7.0
The Raven 1935 6.4
Werewolf of London 1935 8.0
Bride of Frankenstein1936 6.4
Dracula's Daughter1936 6.6
The Invisible Ray 1939 7.1
Son of Frankenstein 1939 6.8
Tower of London1940 6.3
Black Friday1940 6.4
The Invisible Man Returns1940 6.1
The Invisible Woman1940 6.0
The Mummy's Hand 1941 7.4
The Wolf Man 1941 6.1 The Black Cat
1942 5.9
The Ghost of Frankenstein1942 5.9
Invisible Agent 1942 5.3
The Mummy's Tomb1943 6.4
Frankenstein Meets the Wolf Man 1943 6.6
Phantom of the Opera1943 6.1
Son of Dracula1943 5.7 The Mad Ghoul
1944 5.3
The Climax 1944 6.0
House of Frankenstein 1944 5.4
The Invisible Man's Revenge1944 5.3
The Mummy's Ghost1944 5.3
The Mummy's Curse1945 5.7
House of Dracula 1946 5.1 She-Wolf of London
1948 7.5
Abbott and Costello Meet Frankenstein1951 6.7
Abbott and Costello Meet the Invisible Man1953 6.3 Abbott and Costello Meet Dr. Jekyll and Mr. Hyde
1955 6.2 Abbott and Costello Meet the Mummy
1954 6.9 Creature from the Black Lagoon
1955 5.0 Revenge of the Creature
1955 5.7 This Island Earth
1956 5.5 The Creature Walks Among Us
1956 4.0 The Mole People
What I notice about the IMDB ratings is a marked downward trend over time. The sequel films rarely have ratings comparable to the originals. The downward trend is interrupted by breakout successes in films in which Universal introduced a popular new character--such as in
THE INVISIBLE MAN (1933),
THE WOLF MAN (1941), or CREATURE FROM THE BLACK LAGOON (1954)--or a new concept, as in
ABBOT AND COSTELLO MEET FRANKENSTEIN (1948). The cream of the crop are
FRANKENSTEIN (1931) and
BRIDE OF FRANKENSTEIN (1935), which earn very impressive scores of 8.1 and 8.0. As a basis for comparison, 8.1 is the same score IMDB raters give to THE PRINCESS BRIDE (1987) and GOOD WILL HUNTING (1997). The average for the entire film series is 6.49, which compares favorably to the average for the FRIDAY THE 13TH series (4.98), the NIGHTMARE ON ELM STREET series (5.54), and barely edges out the SAW series (at 6.45). The average rating of the first 26 films, from 1925-1940, is 7.06, while the average of the final 25 films is only 5.89 (still enough to beat Jason and Freddy, but now behind Jigsaw).