Lani,
I have personally had a few experiences, my first particular experience is hard to describe but it was on diary farm on which I grew up essentially my siblings and I were playing in dairy roller skating (ah the days before playstations and I products lol) , when suddenly the back up gates came flying up the yard towards us. It is important to point out that there gates had to be pushed by someone at least 12 years old and that was slow going so there was no possibility that it was the wind or that someone was pushing it because it was just a steel gate on rollers so you would see someone pushing and unless there was a tornado the wind could not catch it. As time has gone on I thought it must have been an over excited childhood memory however when I talked to mum about it one day she said she could remember a day when all of us kids came running home from dairy and told her what had happened. The main reason I mention this is there are independent witness to the event.
I have had a couple of experiences since then one of which happened when I was an atheist which made me look very hard at the situation before I changed my thinking. I had a couple when I was attending church ( I no longer go to church) however that was a happy clapper church and think I was just caught up in hype. As mediums and the like I have no personal experience so can't really comment.
I guess at the end of the day all experiences are subject to the individual and it sounds like your craving certainty in this life which funnily enough I can give It to you and that is death and taxes? . I don't know if this will help at all but hopefully at worst it's been an entertaining read.
Paul