Walmart Salsa bowl. $1.50 and its perfect.
Take a pocket knife and carve out a design of your liking. The rough surface aids in making lather.
It's plastic and easy to hold. The link above is essentially what I'm talking about but black.
It's the bowl of choice for many many people here on the forums. It won't break either if you drop it. Width and height are fantastic.
Walmart Salsa bowl. It's a pain to find but it's worth it.
Dollar store has these too. Found 2 for $1. Perfect size, you can drop them and they fit well in you hand. Stumbled into that little jewel and that put an end to my bowl shopping.