As farslayer said, you need to know what video card(s) you have. (Brand and model). 'Easiest' to setup depends on the distro you are using and really depends on the video hardware driver support on that distro. This support is directly proportional to how linux-friendly the vendor of the video card is.
The point is some video cards can be hard to setup and it's not the distro's fault. If setting up your card in linux becomes to much of a hassle, you might consider looking for a linux friendly card that fits you needs on ebay.
Read around, ask around. If your particular card has lots of people having problems setting it up, flick it.
www.pclinuxos.com
I recommend pclinuxos 2007. It has the KDE user interface you might prefer and it also has very easy to use configuration programs.
Most generic video drivers are available. Certain ones such as the 3d drivers from nvidia can be easily downloaded and installed.
The forums site over there is top-notch. You are welcome to visit and ask for help if you have any problems.
hth