This is a cook book that i created yesterday, so objects with high val_block is a candidate to this area.
But be in mind that the objects must be SMALL
SELECT * FROM (
SELECT OBJECT_NAME,VALUE,blocks,value/blocks val_block FROM
WHERE t1.OWNER=’&schema’ and t2.OWNER=t1.owner AND
order by 4 desc)
For more information about buffer pool : http://jonathanlewis.wordpress.com/2007/09/05/hit-ratios-2/