I've got 3 ARs currently.
JG M733, CA/TM M16a2 and a G&P/Systema SAM-R
Its been a 10 months since I was in Iraq, but the M249 stocks discussed a few pages back were extremely popular, but hard to get. I saw several in PMC hands, 1 with a Marine PFC and several in Army hands. Everyone I talked to loved the stock though.
The JG is getting a G&P M733 body and a 2roy M203, the SAM-R is getting a G&P FN receiver and the M16a2 is up for sale to help offset the M249 my wife doesn't know about yet.