If you're interested in webcomics that really experiment with the format, HERO: A story by Hwei goes down a pretty different route than most comics - using only images, and leaving any narrative and dialogue as hover-text that only appears when you mouse over certain panels.
I'm not quite caught up on it, and the latest chapter seems to have a more traditional approach of dialogue and narrative captions - leaving them visible on the page - but that could be just a one-chapter thing.
It's also pretty dreamy and poetic, IMHO.