Hmm... most psychedelic drugs can have you swimming in psychedelic soup if you take enough.
I like what chucky did, describing the differences...
LSD: I give this top ranks because of the quality, diversity, and relevence of the visuals. It's like I'm never seeing the same visual twice. Plus no other drug has blinded me with closed eyes and presented me with the most perfect art ever conceived by man. Everything is bright and beautiful, but a shift of your mood can cause everything to go dark and sinister. The visuals are really connected with your mental trip. CEVs range from blinding bursts of all-colors-at-once to breathtaking artwork to oddball psychedelic chain reaction machines.
Mushrooms: Mushroom visuals are like darker, eerier, more organic and flowing LSD visuals. At night you can watch the air currents drifting through a room like a soft stencil drawing in motion. The visuals compliment the mushroom headspace by adding a strange visual aspect of the trip, but seem more independent of your emotions and thoughts. CEVs are absolutely amazing, like Alex Grey artwork in full psychedelic motion.
Mescaline: Mescaline goes from visually mundane to creating expansive and meaningful trip-scapes before your eyes in seconds. At first everything has a soft and sparkly appearance, then wood grain begins flowing and faces form in it, then the ground starts patterning around your feet and the clouds start to look like a kaleidoscope. Then maybe a neon goddess will appear out of nowhere. You can draw tracers with your fingers through the air which stay there for minutes. The grass blades interconnect and then it looks like the ground is covered with a sparkling spider web. Well, these are things that I've seen on mescaline anyway. This is one drug where if you let yourself get lost in the visuals, you will be impressed, even though it may be able to ignore the visual aspect for much of the trip. CEVs are neon, photographic, or seductive.
2C-I: Kind of like mescaline but much less "creative". Everything is flowing, long tracers occur, and patterns form in lots of objects. But for some reason I find 2C-I visuals mostly repetitive and boring. CEVs are neon and flowery.
2C-B: This one seems to have no character of its own. The visuals vary from anything resembling mushroom, LSD, or 2C-I visuals. Actually it is more like LSD than any other phenethylamine I've tried, except the CEVs are far less interesting (color blotches and fractals) and the OEVs seem to have less variety.
2C-B + MDMA: This combination caused pixellated vision and an "overlay" effect which was like a transparent image of my CEVs presented over what I was looking at with my eyes open.
MDMA: Enough MDMA gives me photorealistic CEVs, true "hallucinations" like seeing things that aren't actually there, pixellated vision, and color blotches moving about the room. I wouldn't be surprised if my "mdma" experiences that were heavier on the visuals had some MDA mixed in.
HBWR / Morning Glory: Almost mushroom like, but brighter and sparklier and less movement in objects. Tapestries may swirl, lights may change colors, and cars may smile at you. But that is at the high end of the visual spectrum with this one. CEVs are often photorealistic images of ancient temples and natural scenes (at least for me).
AMT: Very similar to LSD: the same kind of movement in objects and patterning. The visuals lean more towards soft neon reds and yellows (rather than LSD's dominant bright blue) and the CEVs lean towards the sexy and seductive.
DXM: DXM visuals are lame until you break through to a certain point. When you are having an OBE on DXM the visuals are amazing. I have seen myself as a rock in the road in ancient rome, become a chariot racing around the sun, been part of a crowd at a Phish show, seen a three mile high electric Jesus walk over me, and been transported to a tropical island. All these visions were totally realistic. OEVs can also consist of objects melting, dissipating, and turning into other things. There is a drastic shift in "perspective", and things may appear larger, smaller, closer, further, or angled differently than they actually are.
Cannabis: Enough pot will give you visuals. Things become sparkly, then people can look like cartoons in your peripheral vision. Patterns and sparkly star like things can be seen with your eyes closed. Enough pot will even have objects turning into other objects.
Salvia: Its hard to count this one. The visuals aren't "normal". The floor beneath you will instantly become the wall in front of you, and your body will turn into a bunch of eyes, and then you will be in another world whether your eyes are open or not. The effects of the drug are so potentially extreme that the visuals are not really your main concern.
I guess that's all I've tried, or at least that I can remember right now.