Honestly as much as I love the Nova Corp and am not really a fan of the Lanterns, I don't think any of the corps would be outmatched by them. I'm positive that the Gl's could take them. As much as it is nice if you compare feats the DC people are generally overpowered compared to Marvel. I've lost wayyyy to many arguments being on the Nova side. Now a Nova Prime in a one on one fight versus a lantern would be very different.
The Nova Corps are a force to be reckoned with, but as powerful as they are they don't stand-up to the Green Lantern Corps. The GLs are only limited by their imagination. They don't even have the yellow weakness anymore (except trainees). This is easily the GLs win.