What do you think I should get?

I'm planning on upgrading soon, and I plan on going with an Intel chip, for the reason that i think the hotspot right now is the P4 2.4 with the 533fsb. It is roughly about $195 for the retail version. I also took into consideration the AMD option, and a XP 2400 is $193. So, i think I will go with the better quality processor for the big 2 bucks.
But my question is on whether I should go with DDR or Rambus? I just want to know from people who have either configuration or both and would want to share any performance gains or losses.
Also, opinion on motherboards would be good too, seeing that I will need a new motherboard anyway.

DDR Intel pulled support for rambus.

I would choose RAMBUS.
(Surprised that I disagree with Noo Noo. First time for everything)

The rambus systems are a little more expensive but they are definately faster. Go to www.Tomshardware.com and look at the i850e solutions.

Although Intel have moved away from RAMBUS and will be going wth DDR in future it is a political move rather than a technical one. If you look at the workstations from big vendors they all still use RDRAM.

The RDRAM platforms on market right now are quicker.

I would add though.... that most of the Xeon workstations are coming with DDR.

I'm surprised that it has happened.
Even though RAMBUS inc have shown horrendous PR and business tactics. It still seemed that whenever solutions were compared that RAMBUS was faster when paired with the P4 than DDR?

Well, also, with dual channel DDR coming out, do you think that paying more for the rambus would REALLY be worth it?

First reactions from the tech sites would make me think that it is worth the cash. There's really not all that much difference in it. Everything depends on when you spend your bucks.
You'd have to wait a bit to get a dual channel DDR mainboard.

By which time perhaps rambus will be a less competitive option. I still think that the 1066 RDRAM should have showed the technological way forward.

At the time the Benchmarks show Rambus is the way to go with an P4. I think at this point in time, I would go with the Rambus if I weren't thinking about upgrading for future. If you want to be able to upgrade later, and would sacrafice a little performance then go with DDR, but depending on what comes out in the near future, you might have to upgrade to a new board to use the next DDR version that comes out.