Flash fan page. Why do you love Flash?
I'll go first:
Super intuitive and minimalist UI. Whether you need smooth lines and shapes or grid-snapped pixel graphics -- everything is always in vector until you export it to PNG. By combining its layers with its timeline, you get a sort of 3-dimensional layering system which boosts your productivity by a long shot. Then there's the whole animations / ActionScript universe if you're feeling frisky. The perfect design tool. Like they say: "Flash for graphics, Photoshop for photos, Illustrator for fine arts, and Fireworks for kids."