Definitely depends how much you take, and how sensitive you are..
The Mexican's are usually fun and playful - tripping them I've seen walls move backwards and forwards, lamps lurch towards me, clouds turn into geometric shapes, rugs change from 2d into 3d, really nice closed-eye kaleidoscope-style visuals (especially if taking them outside, on a nice sunny day), marble surfaces turn into flowing rivers, friends' faces morph from obese to thin-looking etc. Of course, these are just warped interpretations of things that are already there; I don't believe I've ever seen any hallucinations of things that aren't actually there ie ghosts, objects.
The biggest thing I ever felt was when I took too much Thai in Amsterdam once, and had an out-of-body experience. I don't mean I floated out of my body to the roof, and looked down at myself(!); it was more spiritual than that.. I believe it referred to as "ego death". I got a look into "the matrix" and to be honest, it took me a good few days to get over it. I thought I'd never take shrooms again, but now I have a lot more respect for the power of them, and because of that they treat me well!