I can't imagine that any system could convert all other systems at the touch of a button.

Whenever I do a conversion, I write a script according to the job in hand. For the most part, it's just a case of recognising delimiters.

I only ever seem to use MySQL as the database these days and its command set is so powerful in terms of conversions and imports that I don't need to look elsewhere.

I don't know if you've ever come across it, but CSVed is an excellent and free CSV manipulator.