I generated supports for this awesome skull that a user sent in (unfortunately I have lost the name). Removal took a few hours, but this print would be impossible with standard chunky supports

from Illuminarti's blog (source link)

from Illuminarti's blog (source link)

from Illuminarti's blog (source link)

From creative3d.co.uk (source link)

From creative3d.co.uk (source link)