I don't really hate anything per say about html, (after all it powers the entire internet) but I do have a few pet peeves about the language. I do get really annoyed that you must close all of the tags after you issue one, and I don't really like how most code editors don't auto-complete your tags for you. I would improve the language in the text aspect of things, as it needs more customization with the font and alignments, as they never seem to work for me. I would dream of an html where you can specifically dictate exactly how you want your text. CSS has come close to this, but nothing natively in html does this.