A bit of a loaded question as there was quite a few different styles to Macronympha releases so it depends on what qualities you are looking for ultimately. Pittsburgh, PA worked so well due to combination of all these seperate elements into 1 release.
As for straight up junk metal abuse with minor post session manipulations Noise Terrorism can't be beat. One side tweaked by Roemer and the other by Rodger and end result is pretty top notch. Some of this junk metal workings also made it's way into the Mother Savage side project (Big Bang Drum Theory is the staple release). Brute Force Ultimate.
If you are looking for the thick, dense walls of noise a lot of the tape material touches upon this to some degree but my favorite is the surprisingly ignored Bulk Density 2xCDR. Between the CDR format and label involved I think this one was passed on by many unfortunately and it's a damn shame as it is one of the better "post glory days" of the project. Another side project worth checking that falls into this range would be OVMN (mainly the Thirdorgan collab reissued on Industrial Recollections). MXM (unofficial collab with Monde Bruits) is another worth noting.
For cut-up perfection a lot of people swear by Amplified Humans and Baroque. Both were reissued perfectly on Industrial Recollections and showcase the more complex side behind the project. I am still on the fence regarding Baroque but when listening back I can't think of another release that sounds even close to this session by Macronympha or any other project out there. Intensive Care CD and Melting Slowly Into Time 12" LP get my vote though.
Should mention that a multiple CD box set of the early Macronympha tape releases has been in the works for quite some time and should hopefully see the light of day this year? Set will include the best of all the early tapes as well as a large amount of unreleased material, rehearsal sessions, various test mixes, etc. Currently linear notes for the set are being worked on as well as layout. Will be worth the 5 years of sweat put into it.