I've outfitted my custom AR15 with Magpul products for 2 reasons.
1. They are pretty damn cool looking.
2. They are pretty damn inexpensive, with the exception of the UBR. $200+
Now lets move on to what I got. I'll list them as I acquired them.
First Magpul product was the Magpul PMAG. I over paid for it. I purchased it locally. So I over paid, and then I paid a few more bucks in Taxes.
Followed by another Magpul PMAG. This one has a window. Got it at the Gun show so I didn't get a deal after you factor in $20.00 ticket/entry price.
Magpul Trigger guard - I love it. Polymer, Light weight.. Looks great. They make one in Aluminum. I'm sure it's just as good. Just $10+ more. Before this I had the straight piece of aluminum that comes with the DPMS lower kit. I think it adds aesthetic value.
My next Magpul purchase was the Magpul Backup Iron Sights. 1st Generation.
I like it, but for another $50 you may get something better. Troy Industries has some cool BUIS, as do others.
Then I orderd my barrell and Magpul MOE in the Carbine length. I was too anxious and put the barrel on the upper receiver.
Next was the Magpul MS2 Sling, but also check out the Magpul trigger guard!
Followed by Magpul MOE Handguard & Vertical Grip (MVG)
It was pretty cool. I still own it, but I like the AFG2 better and thats on the gun now.
I ordered the Magpul AFG2, Magpul 5" rail, and AFG2 at the same time. You need the 3" of rail space to install the AFG2. I bought 5 because the AFG2 is almost 5" long and it covers up what it don't use.
Which brings me to the Magpul MIAD Grip. I feel this grip far exceeds the standard A2 grip. It's meatier and feels better in my hands.