ATi-Nvidia, weird happenings!

[garagestmarien]

First, the specs of my system are in my signature.
I have a Radeon 9600pro, Nvidia fx5900turbo video cards, both AGP fitting.
When I first downloaded and tried to install UE2.9 I had huge problems with the monitor going out of range.
I tried various fixes, which sort of worked, but not with the results I wanted.
So, suspecting that my Nvidia card may have a fault I swapped it for the ATi and everything installed perfectly. Even compiz and wobbly windows etc worked perfect.
But things like you tube videos were very choppy.
I checked as best I could the Nvidia card for faults and swapped it back in place of the ATi, (UE2.9 is now fully installed).
When I boot up I now get the Kubuntu 10.10 splash screen and then the normal login, except I no longer get a desktop choice. (It flashes up after logging in).
With the Nvidia card, compiz and the rest work fairly well, but not as good as the ATi card, but things like Youtube are much better.
So, on my system, it appears that it likes ATi cards better than Nvidia, I just need to get a better one. (I should point out, I used the recommended drivers for each card - and did also try some others but without any improvement and also tried over-clocking the Nvidia, but with no apparent difference).

It seems really strange as the Nvidia has it's on power supply and 256mb on board, plus faster clock and memory speeds, against the ATi with only 128mb and powers itself from the AGP port).
Also to note, the main power supply is not an issue as I have built in a dedicated 450w supply just for the graphic card.

I am now looking to get a better ATi card and wonder if anyone can recommend one that would be good for my system.
(My Motherboard has no spare PCi slots and only the AGP slot for graphics). I was looking at an ATi x800, but there are so many models and every write up says they are the best you can have, I am totally confused.
Help!

[Meister]

Hawk has better info

[Hawks-SOAD]

http://www.newegg.com/Product/ProductLi ... 0%20series
that is all the decent ati agp cards i could find
personally i would spend the money on http://www.newegg.com/Product/Product.a ... 6814161337 only because i had the pcie version working flawlessly ( it is still running to this day)
or a new mobo/computer

[garagestmarien]

Thanks for the info.
The 4760 looks like a nice card.

Found this site to do comparisons of different cards, has proved very useful
http://www.gpureview.com/