I've read that it was an earthquake/fires, amd I've read it was the sea peoples. Nevertheless, civilizations constantly emerged and disintigrated in the fertile crescant and anatolia, building on top of eachother's ruins, like sumeria, babylonia, assyria, hittites, etc. Why did nothing really take the Minoan's place?
In the 15th century BC, around 1430, many Minoan settlements both on Crete and nearby islands were destroyed by fire (we know this from archeological evidence). A popular theory used to be that a vulcanic eruption and a subsequent tsunami wiped them out all at the same time, but it is now known that that eruption took place 200 years earlier and thus couldn't have been the direct cause. Furthermore, while we're pretty sure all the settlements got destroyed around the same time, that doesn't mean they were all destroyed on the same day or even the same year.
The currently accepted explanation is that the Minoan settlements were destroyed by invading or marauding forces. This may have been the Mycenaeans, who dominated Crete for a time after the 15th century, or it may have been other forces after which the Mycenaeans saw an opportunity to move in. What is sure is that after the destruction of Minoan settlements, the palace at Knossos was quickly rebuilt (unlike other palaces elsewhere on Crete). The palace at Knossos soon became the administrative center on Crete for the Mycenaeans.
As to why Crete never came back to power, that is difficult to answer. At first Crete was dominated by the Mycenaeans, whose center of power was on the mainland. Then from 1350 BC onwards there was a general decline on Crete and later too on the mainland. Trade dropped off and population levels fell; the exact cause is unclear. It would take a few centuries before things started picking up again. (Religious activity continued on Crete throughout this period, so there was some culture still present.) Later on, during the time of the city states, there were many small states on Crete which weren't unified (other than all being part of Greek culture and the city-state system) and therefore not very powerful.
To summarize: The Minoan civilization was a quite large Bronze Age civilization. The Mycenaeans for a while took their place but after that there was decline and only a fragmented recovery with many small city states.
Sources:
S. Price and P. Thonemann, The Birth of Classical Europe: A History from Troy to Augustine (p. 24-30 and p. 58-62)
A couple of general reference works on Ancient History
[edit for typography]
The Egyptians were still around for a while after the Mycenaean invasion. In addition, the Phoenicians were a big deal in the Mediterranean for a while. There are probably a number of other civilizations in the Eastern Mediterranean that rose up after the Minoan civilization was destroyed. They were not on Crete, but they did exist.
Finally- the Mycenaean invasion is supported by craniometric studies. There is an observed morphometric change in skull shape in the Late Minoan period that has been attributed to the Mycenaean invasion of Crete. Manolis, S.K. “The Ancient Minoans of Crete: A Biodistance Study.” Human Evolution. Vol.16.2. June 2001. p.125136.