2002 Chevrolet Venture LS Fwd 4dr Ext Minivan (3.4L 6cyl 4A)
We have had our Venture for almost 3 years now, without even a hint of a problem. It gets exceptional fuel economy for a vehicle this size. We have exceeded 26mpg on trips over 500 miles regularly. It's also very comfortable, even on 12-hour rides across the country. Visibility is great, too, and driving one requires little adjustment from other vehicles (cars or trucks), unlike many SUVs which have turning-radius issues that make parking lots an adventure.
All the room. We have seating for 8, and have used it, even with up to 6 of those seats filled with adults, everyone has room and the rear HVAC does a great job keeping everyone comfortable whether it's 90 or 9 outside.
More power. I would buy one with more oomph under the hood, because when you are loaded up, performance largely goes downhill, too. I recognize that this would probably tradeoff the aforementioned excellent fuel economy, but for me, that would be OK.