I would say... 2C-B
~BUT~
it's VERY dose sensitive, so make sure to do your research ahead of time, and START LOW <- can't stress that enough.
At lower doses many people describe it to be very similar to MDMA, but every person's dose sensitivity is different, and with every additional 5-10 mg you could get very different experiences, ranging from the mild empathogenic euphoria all the way to a full-blown psychedelic experience.
That being said, 2C-B has been anecdotally described as much easier on your body than MDMA, with shorter recovery time and lower probability of neurotoxicity.
Anyone else feel free to correct me if I'm wrong, or to add some sources to support/debunk my claims. I wish I could find the sources where I'd read those claims right now, but I'm on my phone in the office bathroom at the moment... ???