As seen here:
A general guideline could be as follows: if you require multi-statement transactions, advanced isolation levels and row-level locking, foreign key constraints, or otherwise have a requirement for ACID features, go for InnoDB. Otherwise, simply use MyISAM, the default.
I think I can restate that just a little clearer: don't use MyISAM.
Less dogmatically, unless you know exactly why you need MyISAM and you have the data to prove that this is what you need, don't use it. Period. And I want to see the data first. And how you collected it. And whether it was in a real-world environment. And I want to know what problem you're trying to solve and why the broken technology of MyISAM is the best choice. There are legitimate uses for MyISAM, but not many.