PNG / SVG (Vector Graphics) sprites quality

I can’t be called experienced in graphics workflow, so maybe it’s a newbie question. Everytime I import custom sprites in Unity, they look not much pretty with sharp pixelated edges and I don’t know why it is so.
I used to think that new Vector Graphics feature would make process easier. But my svg sprites look even worse than png.

Please, explain how I can achieve better quality for both png and svg.

I want to build an Android game and I attached screens with a comparison for 480:320 and 16:10 resolution.

SVG sprites are actually meshes. Turn on anti-aliasing in your quality settings and check the “Allow MSAA” box on your camera.