The most amazing to me is the Eucharistic miracle of Lanciano.
I still get goosebumps when I look at the Lanciano miracle.
Is the miracle in the wafer ?
While I was doing a stint in the adoration chapel a few years back, I read a few of these stories of Eucharistic miracles, among other things.
One common thread, I thought, seems to be that on occasion the bread and wine will suddenly be perceived as actual flesh and blood, and that this commonly occurs because of someone scoffing or scorning at the idea of the Real Presence. In most cases that I read, the miracle is a rebuke or a lesson to doubters, not a reward of faith.
The great miracle is that we receive the real Body and Blood, Soul and Divinity of Christ without having--as our Protestant friends used to scoff, back in the early days of the Reformation--to behave like cannibals. In its way, that is an everyday miracle more miraculous than any of these unusual happenings.
Just as the Mass is a bloodless Sacrifice.