How about white beans (cannellini beans)? Mix together roughly chopped garlic, beans, lemon juice and olive oil and puree in a food processor until creamy and smooth. Spread on the toast and add a few green leaves (basil or chopped tarragon or parsley). If your budget can stretch to it, invest in a bottle or can of truffle oil. You won't regret it! It lasts ages as you only need a few tiny drops at a time. A few drops on top of the bean puree and herbs will transform the bruschetta into a gourmet delight. If you can't afford truffle oil, use a few drops of walnut oil or sesame oil.
You could also make the above using black beans. That would look stunning, contrasting with the white beans. I'd add a few snips of sun-dried tomatoes, as well as the herbs ,for a dramatic effect.