First thing I thought of when reading this title was The Incapacitants "Box Is Stupid" - put that in a space capsule and send it into the universe to let other life forms know what Harsh Noise from Earth sounds like. Also the "Pariah Tapes" five cd set from FA, with just as outstanding material. But anyway, the following are not just for treasuring but for returning to for repeated listens...
Sacher Pelz - "Mutation For A Continiuity". Not only for the essential re-released material, but the very satisfying packaging, chock full of inserts and "information". One of the few items were I don't mind having the extra bits, all being these nice cards reproducing old covers etc., along with some recent poetry from Bianchi.
Being an MB freak I'd also add "The A.C.V.I Tapes" triple cd set and "Teban Slide Art" triple cd set, both from Menstrual. Reasonably simple packaging in dvd style boxes with the usual minimalist design and artwork. Probably wouldn't do you much good if you weren't an MB fan but you either are or you're not.
Le Syndicat - "Thirty Years Of Excess" six cassette box set from Influencing Machine. Just necessary. Been longing for something like this for a while and was delighted when it happened last year. Extras fortunately limited to one simple yet attractive booklet.
Blod - "Red Light Companion" triple lp set. That pure, no-bullshit Harsh Noise all contained in a very handsome box with a few little extra bits of nonsense. The only issue I've had with Blod is that the Noise is divided into smaller pieces. I've always suspected he just cut up longer pieces into smaller ones, which is, of course, his right to do so, but the stops and starts aren't appealing to me. Fortunately, the quality and standard rise above that misgiving and I love having this item.
Etant Donnes - "Tapes, 1977-1983" from VOD. An impulse buy when I saw it in a shop that I have never regretted. Just outstanding, lasting work, always necessary to have when one needs to indulge.
Bizarre Uproar "Fifteen Years Of Filth And Violence", the four tape version (wasn't induced to pay more for an extra tape and a t-shirt). Can't really loose with BU, and I brought this at a height of my interest in this project. Rugged, quality material (although not necessarily his most memorable, however it's been a while since I've listened to this) with a lot of extra bits and bobs if you like that kind of thing.
And I've already banged on about Radigue's "Triology De La Mort" and "Adnos I-III", both triple cds (the former had a limited edition sculpture of a skull one could house their copy in, for an extra fee). Both examples of a continuous release over more than two albums. Both fucking perfect.
Edit - The Rita "Retrospective" release deserves an honorable mention even though it's not technically in a box. That's because artist and label took a different perspective on how to re-release a horde of older material that, so far, I haven't seen replicated. Probably not surprising, but a tad disappointing nonetheless.
