I'm not a big fan of opening lids on fermenters too often. So personally, at this point, I'd go ahead and keg it and get some CO2 on top of it. After it fermented, you had a perfect little beer environment in there. Beer, with CO2 on top and nothing could get in. Opening the lid, checking gravity frequently, that all gives other things a chance to get it, especially oxygen.
So, since your gravity is stable and it's been over 2 weeks, I think it's good time to keg. You can still let it sit and condition in the keg for another week or so if you wish. I just always feel a little safer with a nice layer of CO2 on top of my beer. And more than likely, right now in the bucket, you probably have oxygen in there.