The Sienna will probably be the most reliable. The Odyssey is the next most reliable, and everything else behind that. I think the Kia Sedona (2015 and newer) would be worth a look. Kia makes some of the best mainstream cars now, but still depreciate more than many brands. You should be able to get a Sedona for much cheaper than a Sienna or Odyssey especially. I wouldn't buy the Sedona new unless I got a good deal on it.
The Odyssey is usually more enjoyable to drive while the Sienna is more refined. If you were buying new, Toyota probably has more deals than Honda since the Sienna is getting old and Honda doesn't usually do incentives. That said, the Odyssey is a much cooler minivan because of how new it feels (redesigned last year compared to 2011 for the Sienna). Because of that, I'd get a 2019 Odyssey EX-L. Toyota is expected to debut the next Sienna next year.It was spotted testing this week.
Minivans do almost everything better than SUVs, but if you were to look at an SUV, the Kia Telluride and Hyundai Palisade are some of the best attempts of an SUV trying to be a minivan. They are seriously getting top marks across the board, which is rare for SUVs it seems like.
If it weren't for Chrysler's lame reliability, the Pacifica would probably be the best minivan, especially the Plug-In Hybrid.