All Mesuggah is solid. Obzen and Kolossus are more streamlined (not a bad thing, considering how well they do it), the latter having a more “natural” production, and Obzen having a more sterile and mechanical production.
However their other albums are nothing (pardon the pun) alike:
-Contradictions Collapse (1994) is just another thrash album cloned from Metallica, doesnt worth anyone time.
-DEI (95 or 96) is their best album and imo the best to start. Is a thrash metal album on the surface, but they started using the polyrythms that everyone already knows, and the palm muted “djent” riffs so copied nowadays.
-I cant stand Chaosphere (98 or 99). They try too hard to be so tech in this, but sounds so messy.
-Nothing has two versions: The 2002 one i dont rec to anyone, the audio sounds… broken, for lack of a better term. The 2006 version is REALLY innovative (altough tiresome at times), focusing more on grooves than speed.
-I and Catch 33 (03, 04) are really good, both are one track record but I is only one track and diverse, while Catch 33 is splitted in tracks but is basically the same groove all the way. The concept is really cool btw (paradoxes).
-Obzen and Kolossus are follow ups to DEI, as i said, with different productions and slighty different styles.
Overall a great band. Their sound is difficult to digest at first, but well worth it after that (specially if you´re a fan of prog/tech thrash or death metal… or just DIFFERENT albums altogether).