Most is defined by the attributes you apply to it. "Most of your time" would imply more than half, "the most time" implies more than the rest in your stated set. Your time implies your total time, where the most time implies more than the rest. I think "most" leads to a great deal of ambiguity.
A thing I have never had the time to look more closely into. But I find both variants: What I love most is ... or What I love the most is ... I think the more common form is 'the most', and I ...