Mangosteen, I presume Lucs,the seetest dulcis lines,Russells sweet might be top tier. Achachiuru and related south American species like madruno,lemon drop,bicuda,and a few others might be second tier. Third tier could be sourer dulcis,,brunie cherry with sour ones like xanthochymus in a class of their own.Asian and American members of the genus might be best separated in any rating because they are so different.