Samathabhavana will send one to Brahma world. Where the Brahmas stay in jhanic bliss requiring no food for water nor other nutrients. The life span of Brahma is also very long. But the defect of this Brahma world is that after that long and blissful life a person can revert to human world and apaya world.
Vipassanabhavana if properly practiced and achieve the status where sakkaya-ditthi can be expelled altogether, a person can hope to attain the cherished goal of Nibbana through the path of magga and phala. So among the four kusala deeds the vipassanabhavana is the best.