There are many different definitions of the concept of ego death and I can't say I'm familiar with them all, so I shall go with a definition which I have recently been discussing with a colleague in relation to dreaming and the nature of consciousness itself. If you take this definition of ego death, then I have experienced it a number of times. Not through psychedelics but a form of sleep training and advanced dreaming, to describe it in very high-level terms, a form of meditation if you will.
To me, I experienced this as the bare minimum level of consciousness, the total loss of the subjective self, of spatial and temporal awareness, absence of all my senses, of awareness of my body and mind, absence of thought - leaving only the feeling of existence, the feeling of being alive at this moment. It is a beautiful feeling, a feeling of peace and serenity, of purity, the first time I ever experienced that state I conquered my fear of death. It is difficult to describe the experience without resorting either to metaphysical terms, becoming very technical or implying more phenomenological quality to the experience than there was, for example, it is not akin to laying in a floatation tank in darkness and silence, in this state you have no body, there is no 'physical' quality, it is the purest phenomenological state.
There are other descriptions and variations of the subjective experience that is perhaps more akin to a form of dissociation, I can't say I have experienced those, but what I did experience was a magnificent spiritual experience that really changed the way I think about what it means to be sentient.