I am loving the new 3mm peg system on the NEST/ HFTD line. Its so simplictic, but effective. Its a nice touch for giving figures that don't come with any/much accessories a little bit of extra fire-power I've been scouring through all the figures i recently got to see who is compatible with it, after i got a recon ironhide, and started messing around with the insane level of weaponary that came with him. so far Ive found - Brakedown - can clip stuff to the underside of his hands Brawn - Loads of places that weapons can be clipped to him (looks great with recon ironhides guns) Hupcap - the exhaust pipes on his arms Mindwipe - his legs Breacher - few spots on him. Seaspray - the silver 'ladders' on his shoulders in robot mode. Am I missing anyone?
There are bunches out there. One off the top of my head is that Skystalkers hooks peg into Depthcharge/Sonar's hands. Not to mention all of Recon Ironhide's weapons are 3mm compatible.
You can clip 3mm pegs onto ROTF Scattorshot's guns(more guns!) and onto HFTD Brimstone's bike handles as demonstrated in Vangelus review of said toy &/or Hubcap. Other than those & what you listed I can't think of anything else.
Hmm, never thought to check depthcharge for them. thanks! Can't wait for Straxus to come out. Thanks guys.