Yes. At a Christian conference, a few years ago.
I witnessed a young man who had had surgery on his legs, surgery which had left him with metal plates and scar tissue, stand up and move in ways which he had not been able to do before his surgery. I saw his skin which was free from the scars.
I did not see the x Rays, but I know some were made.
I saw that man, later that night, pray for others in power, filled with knowledge about the people he was praying for, stuff they hadn't told him. And not wishy washy vague stuff; things like - you have a sharp pain down the back of your leg, God is saying this about it and I am praying for it to be fixed.
I've spoken in tongues myself, and I've heard others too. I have been told what one particular sentence I tend to repeat means (as in, it is actually a sentence in a different language, not "just" a supernatural interpretation). I have also whilst praying been given specific information about strangers which I have used in order to pray for them.
I have witnessed people throw away hearing aids after God has healed their hearing.
And, I have witnessed people pray repeatedly for healing which hasn't been received. I've seen close family members die (no, not as result of seeking supernatural healing rather than modern medicine. More when "only a miracle would save them" and it hasn't.
In our church, we had two young adults both have brain aneurysms within a few weeks of each other. One made a full recovery, and has just a bald patch to show for it. The other died. Both had faith, both were surrounded by family, friends, and church members praying.
I have no idea why God doesn't heal everyone who asks for healing, and I have even less idea why he doesn't simply heal everyone, whether they ask or not.
And it probably sounds like a cop out to say that I don't need to. I don't want to go too much into the specifics of my own life, although I'll happily chat via pm if people want to. But i do know that I am content, wether God heals or He doesn't, it is enough for me to know that he is the author of my life.