Every year we get a few new examples of sequels no-one asked for; follow-ups to movies that weren't particularly memorable to begin with but for whatever reason made enough cash to spawn a second instalment in the feeble hope that a franchise might be in the making.

Charlie Day, Jason Sudeikis and Jason Bateman in 'Horrible Bosses 2'
[L-R] Charlie Day, Jason Sudeikis and Jason Bateman in 'Horrible Bosses 2'

The current example is 'Horrible Bosses 2', the continuing adventures of three morons (Jason Bateman, Jason Sudeikis and Charlie Day) who spectacularly failed to take care of their boss problems the first time around. The prime selling point for the original film was Jennifer Aniston talking dirty, so of course that role has been beefed up considerably this time. But critics have slammed the sequel for being even more vacuous than its predecessor.

More: Read our review of 'Horrible Bosses 2'

The current model for these movies is 'The Hangover Part 2', which essentially remade the original film but ramped everything up by setting it in Bangkok. It was universally loathed, but made enough money to spawn a third instalment. Even rarer is the unnecessary sequel that turns out to be better than its predecessor, such as 'Meet the Fockers', a sparky improvement on 'Meet the Parents' (although the superfluous third film 'Little Fockers' predictably flopped). 

On the other hand, there are a lot of part twos that never caught on, simply because no one cared to see the story continue. Among a very long list of these, you'll find the unmemorable likes of 'Grease 2', 'The Fly II', 'Basic Instinct 2', 'Blues Brothers 2000', 'Analyse That', 'The Whole Ten Yards' and, what's considered one of the lamest sequels ever, 'Speed 2: Cruise Control'.

More: Watch the trailer for 'Horrible Bosses 2'

After Horrible Bosses 2, the next sequel nobody asked for is 'Hot Tub Time Machine 2', coming to a cinema near you in February whether you're excited about it or not.