what is a good source for pla filament in the US? I have been asked this question but i dont live there anymore so i dont know.
I don’t print PLA, but I hear Ultimachine has good stuff, and has for a quite some time.
Protoparadigm is my gold standard.
I love my PLA from http://printbl.com. Imported from NZ.
http://printbl.com is out of L.A. they do the importing.
Zentoolworks has good reviews, but I buy 3mm plan from eBay.
Another ++ for http://printbl.com PLA from me. I’ve used many different colors from their store, and had great results.
We sell high quality PLA at http://toybuilderlabs.com, and some of it is now available at http://amazon.com. Our natural PLA is currently available with free shipping, too! http://www.amazon.com/Prototype-Supply-Filament-Natural-PS-M-PLA175-N/dp/B00D6K6MUI/ref=sr_1_1?ie=UTF8&qid=1373403655&sr=8-1&keywords=pla+natural+prototype+supply
Ive bought all my regular PLA from reprapper so far, since I can get more than double the amount of PLA for most other place’s regular cost. It is lower quality, and theres no standard to hold anyone to as far as which supplier has ‘good quality’ aside word of mouth. I’ve heard good results from those above with http://printbl.com which is a NZ company’s imported PLA, protoparadigm, faberdashery and ultimachine (from other sources, excluding these comments). Try to ask the suppliers what their range of deviation in the diameter of the spools are. ideally you want something with +/- .01mm through the entire spool (kg). 1 kg = 2.2 lbs. I’m waiting for the filastruder machines to come close to this standard. 
You also want to make sure the filament is round, since they can come to you with a very oval shape if its not made or handled correctly. (this includes the transportation and storage you utilize as well)
Thank you all very much! I will review all of them and link to this thread so I can make a concise list. Cheers!
Matterhackers has nice stuff and their pro series PLA is amazing. Matterhackers.com