MS paint and Graphics gale are all you need man, they have all you'll ever need for pixel work.
GG is my fav but i still use paint for transparency, never fully figured that out for GG.
Gimp and photoshop are also good,.. though i only use it for fast color changes.
AH i forgot to add, Kolour Paint is fantastic, only out for linux though, it's like paint but much better because of the shortcuts and other things, look it up.