From the Muddy Banks of the Wishkah is the second posthumous Nirvana record, an attempt to capture Nirvana at the peak of its powers on stage.
That doesn't necessarily mean all the band's best-known songs are here -- "Come as You Are," "All Apologies," and "About a Girl" are all absent -- but it does mean that this is the closest representation to what Nirvana sounded like on-stage.
It may not be perfect and it's a little scattershot due to its varied source material (the tapes were recorded anywhere between 1989 and 1994), but it's still a terrific record, thanks to a sharp selection of performances and a set list that relies on B-sides, album tracks, and album favorites, highlighting the group at its best.
It's not necessary, but it still finds a great band in top form.