Blockchain was an incredibly transparent grift. AI is a fascinating technology that's being used and abused by the worst people on the planet and will probably cause society as we know it to collapse. Quantum computers are a very niche, very specific tool that are super cool but get talked about weirdly by the media.
Virtual reality is neat and I think it hasn't really been used as a grift yet. I don't think we've really solved its UX nor explored all its possibilities. It seems like as a consumer device it will be a niche product, but the applications for companies and organizations are very untapped.