I don't often use this word to describe something I've read, but I think it's acceptable to use The Comedy of Errors
. It's not the strongest play of Shakespeare's that I've read, but that's understandable as it is apparently one of his earliest. And of course, occupying the middle ground in Billy Shakes' oeuvre is nothing to sneeze at; to reach such a level of "mediocrity," at least relative to the rest of his works, is an accomplishment many would give a pound of flesh to say they have achieved.
Shakespeare inserts comedy into all of his plays, even those most tragic ones, though this is the first actual comedy of his I've read. I can't say I was rolling on the floor in stitches throughout the whole thing, but I certainly guffawed very audibly when Dromio (of Syracuse) was describing his obese "wife's" appearance, likening her to a globe, and continuing to point out which body part corresponded to which country.