7.8/10 All three movies got the same rating on IMDB. I found that interesting and untrue as most of us would when we review movies. 
By the why I know that I am biased to the last film but I hope that I gave good reasoning.
The Simpsons movie
The twenty year wait was finally broken and the results were not too bad. Everybody loved sipder pig and harry plopper (which didn't get much attention) and the issue they delt with was excellent, you cant go wrong today with an environmental issue. They got all the voice actors and some old writers back (i hate when they change the voice actors) hoever, it felt like they missed something. The old spark from the early days of the simpsons was gone and there weren't may humorous moment. Either they could't make a movie with the early day fame or they lost the magic.
7/10
Family Guy: Stewie Griffin the untold story
Like the Simpsons every body came back for this which was excellent. I remenber really looking forward to the second run of Family Guy because the first run was ground breaking. Unfortunatly I really didn't enjoy the movi, besides the fact that it ran like episodes taped together the sub-plot was a disaster and had no real implications on the main stor. Randomness was taken to far I was getting sick of some sketches and just wanting them to end. I did like the movie premeair at the beginning and end.
4/10
Futurama: Benders Big Score
I was really suprised and excited when Futurama came back, I was praying that this movie wouldn't be bad, I really did not want to ignor it, like the later seasons of the Simpsons. The animation differed from the series but, everybody came back (again) so I didn't mind. Other than that the movie was exceptional, right from the start, after very intelligently mocking the Box network, the classic Futurama humor was back, the math was good and the story line was mind blowing. The sub plot turned out to be a major factor, there was minimal randomness and many points to remenber. The movie didn't run as episodes it ran as a film. The ending was nailbiting, bring on the next one.
9/10
Regards
bendthisfire