If you just use your computer for anything other than playing 3D games, you should be fine using the graphics card that is built into a motherboard. You can also try this option and if you decide to start playing games or would just like better quality video you can easily add this component later on.
You will not need to choose a video card if you picked motherboard 3 unless you intend on this being a gaming computer. Every other computer will require a video card.
EVGA GeForce GTX TITAN - Currently this is the best card, be warned, it's not cheap.
MSI GeForce GTX 670 N670 PE 2GD5/OC - Next up, a high end gaming card that offers ample performance, still a bit pricey.
GIGABYTE GV-R785OC-2GD Radeon HD 7850 OC - A great video card for a very good price. This is likely the one I would pick, it's a good compromise for price and performance.
To pick the best video card, I will look at benchmarks before anything else, I then buy something as high up the list as I can afford that gets good reviews, it's that easy. If you have a card model you want, check the brand reviews, some are much more reliable than others.
your graphics card
requires additional power but you don't have a connector that is the
same shape from your power supply, you can usually buy an adapter
from your nearest electronics store.