All of them were brand new.
Here's my timeline/tally of 360 system ownership:
Units 1-4
The first three were 2005 lanuch week units. I paid for one pro bundle on launch at Best Buy and that one, as well as the subsequent two that I took home that day wouldn't output A/V properly or at all.
So it was three brand new 360s brought home, opened, set up and returned because they were DOA right out of the box.
Now, yes I'm sure some of you may wag a finger of disapproval at me counting each of those BUT, I'm unaware of any statute of limitation that one has to go through to count a system as "owned" and since I brought each one home, and set each one up I see no reason not to count them in my total ownership tally. Granted, if you don't want to count those, that's fine, you can count the first four as one if it helps you feel better about it.
So, the fourth one I got on launch week worked, but about a year later the DVD tray went from opening once every third time I pressed the eject button to not opening at all ever. I was out of warranty at that point and MS hadn't done their universal 3 year RROD extended warranty YET.
Unit 5
When unit 4 failed I bought a core unit on the cheap at GameStop, kept my HDD from my original and played that one for another couple of years before the DVD unit gave up the ghost. About a week prior to it crapping out I did that license transfer to be able to get that credit card off the dashboard and play a few games that were suddently having DRM problems. I could have gone with the extended MS warranty, but at the time, as I said, I wanted the jasper unit, not a refurb back from MS.
Unit 6
Unit 6, which is my current 360 is an Arcade unit that I bought from the Digital Press store. That's the one that I had to wait a year to play about a quarter of the XBLA games sitting on the HDD thanks to my license transfer fiasco.
So, yeah. Whether you want to count my total ownership as 3 or 6 to answer your question - they were all brand new.
Yes, it absolutely is and I hate being the guy that it happened to.