Hmmm, I though Uzamaki and Tomie were among Junji Ito's most recognizable works.
There's also his cat diary.
Unfortunately I've never heard them mentioned until now. I'm just starting Uzumaki though. I have no idea where this is going, I can't wait to read more.
While it's probably his most recognized work, it's probably one of his weaker works since Junji's style doesn't adapt well to having long, cohesive storylines with a stable cast. It's kinda the same complaint you had with Gyo. Tomie is probably better in that regard though since every section of Tomie is completely disjointed from every other.
But I did enjoy Uzumaki, if only because the whole plot boils down to "Man... spirals are just out to get errreebody." and boy, do they ever.
My favorite thing about his stories though, is how audaciously FUCKED his characters are, just for the simple crime of being a character in his stories. It doesn't matter what kind of benevolently simple life you lead, the moment a Junji horror gets involved, there's just nothing they can do but watch as it crushes their lives, their family, their friends, and possibly the entire world. Off the top of my head, the only person to ever be a survivor in ANY of his stories is Mimi from Mimi's Ghost Stories, anyone else from any other story is either explicitly doomed or their fate is left completely ambiguous.