Well, when we're talking about this particular franchise, "great" is highly subjective.
No, they're not cinematic pieces of art, but they sure are fun if you grew up with them in the theaters, as I did.
Indeed, Jason Lives is just about my favorite in the series; just watched it as part of a marathon this past Friday. In part three, Richard Brooker played Jason, but there were massive continuity issues in terms of his look, walk and shape -- if you notice in part two, when he's wearing the potato sack over his head, his build is quite different from what it was in part three, and not much time passed between them (in terms of the film narrative). He also had long hair, a beard and a totally different face in the sequel, whereas in part three, after we see him beneath his mask for that moment after Chris hangs him from the barn rafters, he's bald, clean-shaven and boasts a completely different deformity in terms of facial and teeth characteristics. It made zero sense.
What did he do...shave, cut his hair, change his clothes (remember he was wearing denim overalls in the second one, while in part three he had on jean-like pants and some long-sleeve button-down shirt) and get dental surgery in the time between when Ginny leaves him for "dead" in front of his mother's shrine and when the idiots in the third film arrive at "Higgin's Haven" (which isn't even Camp Crystal Lake)? Yeah, okay.
I can't remember if stuntman Kane Hodder began playing the role in six or seven...