The most visual psychedelic. That is a very difficult question to ask. Because there are very different types of visions. DMT is on a class on its own as for strict visuals. It's a "in your face" visual compound. With DMT Visuals are solid and more real than real, if that makes sense. yet, despite the visual intensity there is never a total ego melt and total participation in the hallucination. That's for me at least, but I've had my share of intense DMT experiences, so I have some experience.
Salvia is also different, but is on the other end of the scale. Not as dramatic as DMT, but salvia transports you to a total different and real space and time. although not as clear as DMT, the sense and the "illusion" (really?) of participating is MUCH more intense. MXE (at a hole dosage) also has for me really intense reality shifting perceptions, that in a way are similar to salvia, but in a much less violent way
Other psychedelics like 4-Aco-DMT, mushrooms, 2C-E, DOC or 25C-NBOMe are more or less in the middle and can provide the poweful DMT vision coupled with a similar salvia immersiveness. 4-AcO-DMT, for instance pushes more to the DMT side, while 5-MeO_DIPT (yes, foxy) allows for some outlandish experiences. The balance between immersiveness and visuals is complex and the best visual experiences are ones that stay in the middle, sometimes providing the best of both worlds.