Proffitt's for used parts and kick arse suspension stuff:
http://www.proffittscruisers.com/
Can't forget Marlin:
http://www.marlincrawler.com/
Best High Steer Arms:
http://www.4x4labs.com/ see Luke.
Bobby Long:
http://www.toyotasuperaxles.com/
Traiter Gear:
http://www.trail-gear.com/ I have and will buy stuff from them, but they are importing a lot of Chinese cast items and some folk have dispauraged them due to Marlin issues. I prefer to support businesses that make stuff in the USA wherever possible, versus a business that might have a higher profit line from importing stuff. Nonetheless, I've found alot of their stuff to be of good quality and well - and I will buy from them if there's not an american vendor for the same product. Then again - I was really pissed when I found my WE 17" beadlocks were cast in China - that was just wrong at $400 a unit. Make your own decision.
Lots of good custom suspension stuff and chromoly rear axle shafts - although verdict is still pending on how they're treating me on a possible warranty issue - we'll see:
http://www.polyperformance.com/
Gotta stay local - even thought they're not pushing their site - these are guys you've wheeled with at GSMTR - one of the South Florida Todds - you might even have one of the freebie camo caps he hands out:
http://www.landcrusher.com/
Tons more...
Trollhole
Pepe
Sputnik40
that took 2 years of my life and pissed off the 
Linear Mode
