InnoDB and Memory are really the only ones widely used these days. After Oracle bought MySQL they threw their full backing behind InnoDB and recommended all MyI

InnoDB and Memory are really the only ones widely used these days. After Oracle bought MySQL they threw their full backing behind InnoDB and recommended all MyISAM users migrate. They fixed a number of small problems like the missing full text support. InnoDB is more fault tolerant and modern feature rich (e.g. Foreign keys) than MyISAM. MyISAM is faster in practice despite Oracle’s continuous claims to the contrary. MyISAM is largely undeveloped at this point. MariaDB hard forked MyISAM into Aria and have included better fault tolerance and other general improvements. It’s what I use for my personal projects. Memory tables are strictly in memory and useful for doing very quick processing on things you are certain will fit entirely into system memory. Their data is lost when the system is rebooted or MySQL is restarted.