Marlowe: Dr Faustus and Other Plays, eds. Bevington and Rasmussen. Oxford.
Jonson: The Alchemist and Other Plays, ed. Campbell. Oxford.
Shakespeare: you may use either of the following two editions:
The Oxford Shakespeare (ed Wells and Taylor)
The Norton Shakespeare (ed Greenblatt et al.)
Both editions have their pros and cons. Indeed, the main reason for allowing multiple set texts is to encourage you to compare and critique different versions of editorial and critical authority. There is no ideal or infallible Text of Shakespeare's plays. There are no definitive introductions. All of the above editions are, in their different ways, controversial. The ability to recognise, understand and challenge editorial decisions and critical standpoints is a key skill you will develop over the course of the module.
How, then, do you decide?
1) Do you want annotated texts? If yes, buy Norton. If not, go for Oxford. The Oxford presents a 'clean' text with a glossary at the back of the book. The virtue of an unannotated text is that it invites you to make meanings for yourself in the absence of a strong editorial steer. The uncluttered layout of the Oxford is very good for some readers and for getting a sense of the long-distance movement of the action. The Norton, on the other hand, offers on-page glosses and notes.
2) Do you want an introduction to each play? If yes, buy Norton. The virtue of the Norton's introductions is that they are quite full and are also written by four different critics; the drawback (it could be argued) is their almost uniform New Historicist theoretical bent.
3) Sample each edition:
The best thing to do would be to go to the library or a bookshop and dip into each edition. If quality of paper matters to you, you'll feel differences. If you tend to write a lot of notes on your texts, it will quickly be clear which edition offers you the most room for self-expression. If introductions are crucial to you, sit down and read one from each. (You can also 'Click Inside' the books on Amazon, Google Books etc)
4) Talk to this year's third-years. See what the Shakespearienced advise!
Finally: spend as long or as little time making this decision as you like. You could mull it over or you could click on Amazon in seconds. Either way, as long as you buy one of the set editions you will have a book that is wholly adequate to the year's study.