Easy Paint Tool SAI
My laptop died a few weeks ago, and this meant that the digital art applications I used would be unable to run on this second-hand laptop. Eventually I stumbled upon an awesome digital art program that combines the brush versatility of Corel Painter (there’s Painter 11 out now, can’t wait to try that out) and Photoshop’s interface. Corel Painter X has great brushes but chomps up your computer resources if you use layers in your painting and – this is just silliness on my part – I’m still not entirely fluent with using the software. I always had to switch between Photoshop and Painter, and the layer compatibility isn’t always up to scratch.
I found Easy Paint Tool SAI [fan-made English language pack here], and I love it. It has real-time rotation (PS doesn’t have it olol) and a basic set of brushes (pen, brush, marker, airbrush, water, acrylic, paper, crayon). It doesn’t have the features of Photoshop like selecting and rotating certain parts of the painting, text or fancy filters, but it’s very lightweight and loads in seconds. It’s literally pick-up-a-brush-and-start-painting: the strokes are absolutely smooth, and like most digiart software, the other end of the pen is configured to switch to an eraser. There is also layer and blending modes, hue/saturation toggles, canvas size configurations etc. It’s PS and Corel without frills. 
Using my Wacom Bamboo I did a speed(ish) painting, and I really loved the blending of the brush.
(I need to refine my technique or something, bleh)
Here’s a better artist that can show you what SAI can do:
Happy Easter! I hope it’s full of chocolate.