The fact check link posted by the other user is good.
Newsweek tends to take some news fact, often not even fact but a possible outcome of some developing story, and write a full opinion piece on a tangent.
We get a lot of Salon articles here doing the same thing.
As far as reputable, I would say apnews, Reuters, politico, CNN, BBC off the top of my head.
I know CNN will be contested. They have an annoying amount of opinion in their stories, but I do find that they clearly separate what's objective fact and what's editorial opinion.