How large does it have to be?
The Buick Encore is smooth, quiet, and reliable, but is small.
The new Honda CR-V could be a good fit. I haven't driven one yet, but the previous CR-V had a smoother ride than the current Toyota RAV4. Seat comfort could be more of an issue, as Hondas haven't always done well here. Maybe give them six months to work out any initial bugs. Past CR-Vs have been among the most reliable models in our survey.
In the next size class up, the Toyota Highlander is the most reliable model, and in my review I noted that quietness and smoothness were strengths.
I really like the comfort of the Volvo XC60, but unless you mean "won't leave me stranded" when prioritizing reliability, and not "unlikely to require even minor repairs," it's probably not the best choice.
The new Mazda CX9 drives very well, but its reliability remains to be seen.