For me it comes really close between Legend and Anniversary but I might say Legend.
While we're on the subject, for those who like Legend and Anniversary, do you feel compelled to FanonDiscontinuity Underworld? It is my least favorite of the three as the gameplay is not as fun as the first two, but it has important plot points regarding Amelia and Natla (though Natla could have been presumed dead in Anniversary, and Amelia is found dead, or undead).
(Maybe I should replay them, it's been 10 years since the last time and I had lots of fun watching Magemasher play Anniversary)