Twelfth Night and As You Like It - I've been hearing for years that these two plays are the same play, and while I had acknowledged their obvious commonalities (female characters cross-dressing, pastoral escapism, marriage endings, plucky woman sidekicks) I always felt that the two differed in tone in that the former was more social serious and the later was much more grounded in the pastoral tradition, what with Orlando's bad poetry on the trees and the homosocial, courtly love flavor Ganymede brings to the mix. While I still think that difference exists, I am no longer convinced that it is an important one, mostly because I have read Middleton and Dekker's The Roaring Girl next to those plays now. Moll Cutpurse is so much more transgressive and progressive than both Viola and Rosalind for several reasons. First, she doesn't cross-dress to pass as a man; she does so in order to take advantage of the freedoms afforded the wearers of men's clothes. her visible femininity is still apparent, so she openly criticizes ways that gender is socially constructed, unlike Rosalind and Viola, whose ultimate goals are heteronormative marriage. Second, Moll recognizes how marriage can trap women, and that the social mobility it may afford them is possible not worth its cost when she says things like (paraphrasing here) marriage is just a swapping of places wherein a maiden trades one head for a worse one. For me, this statement negates the supposedly transgressive ending of Twelfth Night in which Orsino asks "Cesario" to remain in men's clothes for their wedding; at that point, what could have been about female empowerment is now about male sexual fantasy.
Last and most important is the issue of class in all three plays. Maria and Celia have their own plats, but they mostly serve as comic relief, diversions from the slightly more serious entanglements of their social betters. They are not given the opportunities to move up in rank that Rosalind and Viola are. Indeed, in Maria's case, class positions are so stringent and internalized that she cruelly mocks Malvolio's social-climbing efforts. On the contrary, the three merchant mistresses in The Roaring Girl, while they do occupy secondary plots, also offer a more nuanced vision of how constructions of class and gender overlap, as well as being aware of how they can use those constructions to their advantage. This is most evident in Mistress Gallipot's affair with Laxton.
Ovid's Metamorphoses - I actually read this a while back, along with Venus and Adonis and The Rape of Lucrece. I waited to post because I was a little overwhelmed with all the raping. In addition to that motif, Metamorphoses also shares themes of Petrarchan inversion and miscommunication with those two poems. What struck me the most was the matter-of-fact was that rape is discussed in Ovid, as if it is a fact of life. In many cases, the god rapist (usually Jupiter, though Hades does this too) tells his female conquest that she is lucky to be raped by someone of such a high station. There's also not a lot of moral judgement present in the text, though that's true with most of its events.