I'm a Pixel Artist/Digital Painter/3D Artist. Check out my DeviantART, AlainGalvan.DeviantART.com to see some examples of my work.

For pixel art, I actually use Game Maker Studio, it's REALLY good for that sort of thing.

For Digital Paintings, I tend to lean towards Photoshop because of the low resolution of my tablet. Unlike open source painting programs where things tend to be pixel by pixel, photoshop paints with vector strokes, which will prevent artifacts when painting.

For 3D, Blender's my main tool, since I can polysculpt and apply multiresolution similar to what you see in programs like Autodesk Mudbox. Zbrush is probably your best bet for 3D work.

As for Hardware, get a wacom bamboo tablet. Best investment eva!

I use Photoshop for everything from my game art to digital art. Not sure about this diference that Alaiin mentions between pixel art and digital art. I just think of it all as art. Gimp is supposed to be a good free art program if you are looking for something similar to PS

Here is my site if you want a look -

https://sites.google.com/site/stephenwinterflood/

GraphicsGale free version is what I use, and I believe it is the best pixel art program out there

Tile Studio and Microsoft Paint... You can be surprised ; )

I wouldn't say I'm really good with art exactly, but I agree with Winterflood and highly recommend GIMP as a free, open-source alternative to Photoshop. It has most of the same nifty features and is, in my opinion at least, easy to learn and use.