that should have been the ultimate imax trip 
(ROOT (S (NP (DT that)) (VP (MD should) (VP (VB have) (VP (VBN been) (NP (DT the) (JJ ultimate) (NN imax) (NN trip)))))))
(ROOT (S (NP (DT )) (VP (MD ) (VP (VB ) (VP (VBN ) (NP (DT ) (JJ ) (NN ) (NN )))))))