Simple answer: The XA2, or if you're a bit nervous about the outcome of the war and you don't want to invest that much, the A2 delivers the goods at an already great price, add in the promo for $100 off, and it's a super deal...also, kinda depends on what your TV's native rez is? Mine is 1080i, so the A2 was the ideal match - if things keep going well for HD-DVD, I'll upgrade both my TV and whatever gen HD-DVD player we're up to in a couple of years to 1080p, but for now, the A2 @ 1080i on a new 65"RPTV is pretty effin' sweet as is!
Edit: Sorry, I didn't even factor in the audio - but then I'm not a junkie with that aspect of it, but you will need to do some homework on that - do you have an HDMI receiver, etc...