Our contenders were the Odyssey, the Quest, the Sienna and the Town & Country. Here's what I found:
Town & Country - it was shorter than all of the others and offered the least third-row legroom, which is important because I regularly have adults back there because my toddlers are in the second row. The third row was difficult to access as well. I think this is a good option if your kids are older and don't need boosters or car seats.
Quest - I didn't even drive it off of the lot. I hated it. I hated the console and the controls and how it handled the tight spaces of the dealer's lot.
Sienna - This was the front runner for a long time before we started seriously considering minivans. We rented one to drive from Long Island to Cleveland with my then 17-month-old and 6-month-old. Once my husband and I had my two and my girlfriend's two in their seats and my friend and her husband in the van, as well as two double strollers and a load from BJ's, I was sold. I liked how it handled and how roomy it was. Then I drove the Odyssey.
Odyssey - this is the one we ended up with. Not only did we get a fantastic deal from Huntington Honda, it was by far the leader in both safety and performance, as well as look, which was (superficially) important to me. I *never* feel like I am driving a huge, long car - I am just as comfortable as I was in my Camry. My kids are close enough to me when I'm driving, the controls are easy to use and very accessible, the storage is fantastic. It handles beautifully and has a great turning radius, a quiet engine and it's highly customizable. Hondas are really phenomenal cars.
Good luck!
L.