OneRepublic shot to fame with their international hit Apologize whereas Dragons, though had had some hits before, officially entered the mainstream rock music by Radioactive.
They both have amazing lead vocalists with producing/writing talent: Ryan Tedder and Dan Reynolds. Dan's begun featuring in some songs like Avicii's Heart Upon My Sleeve.
We'll see with their next album. OneRepublic has a potential smash on their hands with Counting Stars. Its doing well WW right now but Pop radio in the US has not seem to start picking it up yet which makes me sad
Don't forget that Dragons have topped Rock Chart 22 weeks consecutively, while Apologize was ranked number 50 on Billboard Hot 100's All-Time Top Songs list from the chart's first 50 years.