Fashion Armor and Murder Armor for Faces.
Loads of awesome new Archery and Thrown Weapons. Great for a throwing adept, especially when wrapping boom-bolas with Wireless triggers on 'em. 'Well, yeah, you could try screaming or escaping, but then you get bisected by those grenades. Now, if you were to give us a good voice sample and the key to the armory, I reckon we'd be happy to send you off to change into a fresh set of pants and a new job.'
Ash Arms monofilament chainsaw, especially underbarrel. Bye-bye, barrier ratings!
I would like to say the AA16, but sadly since we have lost the ability to use non-standard or extended mags/drums its utility is significantly compromised for suppressive fire.
Once the errata comes out, maybe I'll be able to say the Ares HVAR or the Vindicator minigun, but until we get some supplemental rules on those they're pretty meh.
If the forearm guards can mount any of the stuff that the shadowtalkers mention (cyberweapons, decks, etc.) they could really take top place.