I answered all of that in my last post. I have a samsung, and use Verbatim CDrs, and Ritek/RiData DVD-R's 95% of the time. My Samsung reads everything I've ever thrown at it pretty much. It's read CDR, CDRW, DVD-R, DVD+R, all of varying companies. I've had Memorex, Maxell, Verbatim, and LiteOn CD media in it, and Memorex, Ritek/RiData, and generic DVD media in it with no problems.
Go to NewEgg.com and search for Ritek or RiData. Those are the best DVD-R's you can buy IMHO. I use them for all my computer backups, dvd-video, backups of my DVD movies for my dorm room... they are great. I've had them work great in my PS2, Xbox, computer, and 2 or 3 dedicated dvd players including a 5 or 6 year old Sony in my living room.
There's nothing to really be confused about. You just need to experiment. If you have a Samsung, you're 90% gonna have no troubles at all, Philips a bit less, and Thompsons even more so. Then start testing media. Assuming your xbox is modded, burn a CDR with an emulator on it, see if it reads... then try CDRW, DVD, etc. If a Philips or Thompson doesn't read 2 or 3 different types of CD media, you can pretty much bet that it will never read CD media without modification.
Hope that clears things up a bit, if not let us know what's still confusing, I'm sure someone here can help you out.