I use Adobe Illustrator for pixel art, its fantastic!
You can always go back and save the artwork in a higher resolution without loss of quality if you plan on making a game that takes advantage of different resolutions.
Corel Painter is also very nice and very user friendly. You might want to try the free trail as well.
Develop games in your browser. Powerful, performant & highly capable.
If you want to do simple sprites you could go for Pickle or GraphicsGale.
There was a topic about graphic softwares in the tools/ressources sections but i couldn't find it anymore.