I remember actually studying Twelfth Night but I don't think I actually read it. I hope my lecturers don't read this blog. One of Shakespeare's most successful comedies, Twelfth Night concerns Viola who survives a shipwreck but thinks she has lost her twin brother. She decides to disguise herself as a man and enter the court of the Duke. Another plot follows Malvolio and the tricks played on him. Shakespeare has played with the idea of twins and cross-dressing before (in The Comedy of Errors and The Two Gentlemen of Verona respectively). Malvolio's plot is the better plot, in my opinion, because it is just hilarious. Malvolio's attempted wooing of Olivia is one of Shakespeare's funniest scenes. 
 The crossdressing of Viola seems kind of strange because there isn't an overall explanation as to why she does it. She just arrives in Illyria and is like, 'huh I guess I better dress as a guy!' It's a strange plot hole. I do think Twelfth Night is one of Shakespeare's better comedies but, like in The Merry Wives of Windsor, there is a mean streak running through the play. Like Falstaff, Malvolio is the butt of a joke played by a large part of the cast and at the end of the play he runs off cursing the lot of them. Why is everyone so mean to Malvolio? Yes, he's a bit slow and a bit dim but really doesn't deserve what happens to him. Apart from these qualms, Twelfth Night is a good and funny play. (Also, Mark Rylance and Stephen Fry's Globe production is phenomenal)