Reviewers generally consider the RE1 remake on the Cube as the definitive version of Resident Evil. I'm actually borrowing the all the GC Resident Evil games at the mo and playing through the remake.
I can tell you this with certainty though, the remake is ALOT more difficult than the original PS1 game, it really is a hell of a load more tougher.
Excellent game though, definitely worth getting.
As for 2 and 3, they're simple ports, the same PS1 visuals with a slight touch of smoothing to them, nothing special but worth getting all the same because they are brilliant.








