I agree with Locke. The quantity of humor in a specific title depends on the specific atmosphere the developers had in mind for the game.
Something that I'd like to see more, however, is blaming serious elements with more humorous or comical ones. This was done especially well in The Wind Waker and Skyward Sword. In the latter, Link started out on the peaceful and seemingly unharmed Outset Island. By game's end, he found himself face to face over tumultuous waters combating Ganondorf. The deaths of both King Daphnes Nohansen Hyrule and Ganondorf in that game strike a particularly strong juxtaposition with the game's overall light-hearted tone. In Skyward Sword, Ghirahim is the perfect embodiment of a menace out to capture Zelda and prevent Link from rescuing her however he clearly has some clever and hilarious lines and enjoys toying around with the hero a bit too much.
Overall, humor is an additional spice added to the already excellent Zelda titles and should be used rationally whether it be to provide an effective transition in the side or main story or provide a sharp contrast between certain aspects of a game.