The shadow of Steve Albini looming over that customized super rad guitar head that is a signature of the bands live performance. The originality of this band even goes into the detail of how Steve attaches the guitar to himself.
Todd Trainer, one of the best rock drummers out there that you probably won't see in drummer mags like Modern Drummer or some Hot Licks Video. Todd also does a solo project called "Brick Layer Cake" that is a departure from Shellac but still engaging musically if you've got the ears to check it out.
One of the best Bass tones I've heard on record and live is Bob Weston. One of my all time favorite records is a band Bob joined in their later history " Volcano Suns". "Career in Rock" is a gem of a record to this day, with some of the coolest songs that were never heard on the radio.