The new Oakley boots are pretty comfy but only lasted me about 6 months, their outer sole is soft and it sucks trying to manage the bullshit shale terrain in bumfukistan.
The nike boots are good as well but with a harder outsole that will take a toll on your feet after a while. They have a new jungle outsole offered as well.
My comfiest boots would have to be the "summer" garmont 8 inch boot for rucking. They don't breathe as well as the oakleys but they offer a lighter version of that as well that I haven't tried.
I've had some pairs of danners, but they didn't fit right for me.