The biggest people carrier/MPV type size you will find only seats 7 people, for 8 seats or more you need a minibus. I don't like MPV's in general but out of shear necessity I find myself owning a Galaxy. Much as I dislike them the Galaxy is a great car. I have 3 small children and it swallows up huge amounts of freight including pushchairs, grand parents, IKEA purchases and all the camping kit without needing a roof box. It is only 2 inches longer than an S-MAX but due to the box shape rather than sloping roof at the rear you can carry a huge amount along with sufficient space for adults to sit in comfort on the rear row of seats (I have sat there myself).
After an extensive search the Galaxy got my vote and 2 years later I am still happy with it, the 2.0 TDCi is surprisingly fast if you are in to that sort of thing, technically it is as fast as the Audi A4 Avant 1.9 TDi we had previously, obviously handles much worse and the gearbox is horrible (but works), it is quick if you do want it to move. It also reliably returns 45mpg, pretty impressive for the size.
When we no longer need the space we will re-adjust to a large estate car, but for the category the Galaxy is a tricky one to beat.