Transformers: Dark of the Moon (2011)
Chosen by me as I like to go to the cinema a lot.
Though in most respects a significant step up from the second Transformers movie, and after an interesting, clever opening re-framing the 1969 Moon landing, it is still almost completely worthless.
It spends a whole movie length of running time setting up a pointlessly complicated plot, running horrid 'comedy' bits with Witwicky's family (seriously why the hell are they in this?) and dropping zingers on a missing cast member (I'm no Megan Fox fan but her replacement could be a blow up sex doll for all Bay cares about females).
The action is marginally clearer than the last efforts but again the set pieces only really work in isolated five second moments. Strung together they become non-sensical and at times whole scenes seem missing (we go from Bumblebee rescuing two humans to suddenly having been captured with no linking material at all) despite the fact the film is fucking two and a half hours long.
It also seems intent on hiring people from shows and movies I really, really love (Alan Tudyk and Ken Jeong have extended but pointless roles, Scott Krinsky from Chuck pops up for a single gag) so I fully expect Simon Pegg to be in the next one.