Best card for $150?

Probably the ATI 4870. You may be able to get a 4890 for under $150 including rebate, which is basically a 4870 at higher clock rates.

Would it be worth waiting until I have more money. I could probably pull $200 together in a few weeks.
What I mean is will the card I get for $200 be a whole lot better than the card for $150

Not really. The next real step up is the $300 5850...in somewhat limited supply. I'd either go with that 4870/4890 or save up for the big upgrade.

Thanks for the info. I was starting to go blind staring at all those bench marks.
One more question. Do you think I will see a big differences between the 1950 and the 4870/4890.
I mean the stats say there is pretty good bump in performance. Sorry to keep asking dumb questions, but money is pretty tight right now and I want to try and make the best purchase.

If you're in the US, and can wait another ten days, a Black Friday deal may let you really stretch your money.
And, what brand/model of PSU do you have? A 4870 needs a quality 500W unit. If yours is as old as your x1950Pro, it probably has a little red voltage switch on it, which by today's standards means it is NOT a quality unit; and/or its aging capacitors may have reduced its capacity. You should be able to pick up a decent 80+ certified 500W PSU (e.g. Antec, Corsair, PC Power & Cooling, Seasonic, or Enermax) for $50-$55. If that chops into your video card budget, not to worry. Even a HD4850 is eight tiers better than what you have now.

Yea, I am in the US. I did not think about the PSU, thanks for reminding me!

I actually have a friend that has a spare 500W PSU. I am currently running a ~400W PSU. I think I will go for the 4850.

Thanks again for your opinion