best color correction programm?
 

sometimes FCP color correction just seem too limited to me. why don't they just make a video version of photoshop????

Take a look at:

Final Cut with plug-ins: Color Finesse, Magic Bullet Editors (easy), Graeme Nattress' film effects (good value), stib's curves (free), etc.

Combustion + Color Finesse

After Effects + Color Finesse - Adobe makes AE and it's kind of like a video version of Photoshop?

Final Touch http://www.siliconcolor.com/products/index.html

And if you really have lots of money:

software-based digital intermediate:
Quantel iQ (considered the best right now; about a million dollars)
Discreet Lustre

hardware-based DI (more common, faster, not as flexible or not as many tools):
dv vinci 2k
and many others

2- What exactly are you trying to do?
Color correction in Final Cut is pretty decent except for the lack of a built-in curves plug-in.

bingo glen... working without curves is a real pain in the a**!

If you need SD output Final Touch SD

http://www.siliconcolor.com/products/ftsd/ftsd.html

is not a bad option for <1K. They claim good integration with FCP via XML export/import. It doesn't work with the graphics card coming with your garden variety G5, needs a RAID capable of ~50MB/sec and don't expect a typical Mac user interface, it is VERY much UNIX.

Unfortunately the ColorFinesse v2 upgrade is not much of an upgrade, it costs ~2k, works as a plugin for AE only, still needs rendering...