These are difficult questions, as there are no clear answers, but searching for answers can still be an illuminating process.
In regards to question #1, there are many published versions of Macbeth. Each version has differences in punctuation, and some versions will even change lines to be more comprehensible to a contemporary English audience. Many theater teachers and producers will craft their own version of the play when they produce it. In regional theaters, such as the Guthrie Theater or Steppenwolf, a dramaturg will often pull passages from the First Folio, or from standard texts like the Riverside, to create a version that fits the theater's needs. Unlike contemporary playwrights, there are no royalties or regulations when it comes to producing Shakespeare, and so the productions of the play tend to be wildly different. However, if you must find a specific text, a good place to look might be on Amazon since they rank their bestsellers. The bestselling version of Macbeth is currently the Folger Shakespeare Library's version of the play.
Now, on to question #2. It is also difficult to pinpoint the most famous production of Macbeth, although it is less difficult than finding the most performed version of the play. A person's opinion on the "best" production will depend on how they like to see Shakespeare performed. Do they prefer adaptations? Original practices? These opinions will alter someone's perception of whether or not a play is spectacular. In regards to filmed adaptions, this link can be illuminating. In regards to live performances, there are a few touchstone productions that are frequently mentioned regarding Macbeth. You could say the best production was (1.) the original production starring Richard Burbage, (2.) David Garrick's production in 1744, (3.) Robert Elliston's production in 1809, or (4.) Gregory Doran's production in 1999. Of course, there are countless productions to choose from, as the play has been produced for centuries and each production is different.