MDMA is pretty much the only thing in terms of epic spiritual euphoria. I remember someone said "with ecstasy you feel everything, with heroin you feel nothing"
Quite true. It all depends on what you're looking for. There are substances that will give you a huge sense of "who you are in this world" type of feeling, and others that are simply just pure hedonism, like heroin/crystal meth.
MDMA does a pretty good job of covering both grounds, making you feel physically good and also giving you a profound spiritual feeling of being alive and one with the world.
You don't really get that on opiates, at least I don't. Nevertheless, I have a hard time turning them away.
LSD and other psychedelics can be quite euphoric, especially mushrooms because they allow you to "imagine feeling like..."
For example. while dosed on acid, i feel like i can absolutely make myself feel as if i was on coke, or mdma or whatever just by merely thinking about it