Here’s a comparison between Metacritic and IMDB for each film. (I converted IMDB’s rating from something like 8.1 to 81 in order to match.)

The Phantom Menace
Metacritic: 51
IMDB: 65

Attack of the Clones
Metacritic: 54
IMDB: 66

Revenge of the Sith
Metacritic: 68
IMDB: 76

A New Hope
Metacritic: 92
IMDB: 87

The Empire Strikes Back
Metacritic: 81
IMDB: 88

Return of the Jedi
Metacritic: 53
IMDB: 84

The Force Awakens
Metacritic: 81
IMDB: 81

The Last Jedi
Metacritic: 86
IMDB: 78

Metacritic ranking:
ANH
TLJ
ESB/TFA
ROTS
AOTC
ROTJ
TPM

IMDB ranking:
ESB
ANH
ROTJ
TFA
TLJ
ROTS
AOTC
TPM

IMDB favors the prequels over Metacritic by an average of about 11%. ANH is close between these two, though ESB is higher on IMDB. ROTJ was enjoyed much more by IMDB, by 31%. TFA was a perfect match, and TLJ was an approximate inversion of any of the prequel films, with critics enjoying it more than fans. The only other film Metacritic favored over IMDB was ANH by a small margin.