There's a lot of different stuff that'd be cool to try, but you also have to remember that mindset & setting is very important - I haven't seen a lot of stuff on that here. Usually unless you're taking something like benzos, opioids, dissociatives which can be quite relaxing regardless of your circumstances, your mindset/setting can really affect how the course of a drug will go.
Like shrooms for example, they're fucking awesome but if you're planning to CTB it might not be that great of an idea and might make you feel more like shit (granted, you're gonna die anyway but why suffer for the experience?). This is why it's often recommended to prepare in advance for a trip instead of taking it impulsively because you don't give a shit about the consequences at the time. They can really make the bad thoughts and feelings percolate to the surface, which is especially more dangerous if you're prone to delusions and/or psychosis. Weed, too - some people are fine on it, others get horribly anxious and get bad panic attacks on it.. which is weird, because there's people that do fine on psychedelics but just can't handle weed.
I don't know much about MDMA, but I haven't heard of people having a bad time on it myself. It can even be done at home although it's a little more uncommon than taking it in a social settings. My first time taking it (well I took 6apb, which isn't exactly MDMA but it's very close in structure and effects) I took it at home and I was fine, I just did the usual stuff I did except I enjoyed it a lot more. Also can make you more rambly and lovey dovey so it'll probably help if you have someone to chat with in the meantime, which I did. Although I have also read that people who take it at home find it makes them feel lonelier. That will be something you'd have to research and decide on your own.
Someone here mentioned Datura, and while it belongs to an interesting class of drugs with interesting effects if doesn't have much recreational value if that's what you're looking for. It's a deliriant that makes you hallucinate, but unlike with psychedelics you won't really have insight into your hallucinations - so instead of thinking huh it's making me see spiders, you're going to think holy shit there are actually bugs in my room.
So it ultimately depends on the kind of experience you're looking for. Once you find something you think you'd be interested in try to research it and plan accordingly.