Its an old argument, but you have never been able to quantify how much the battle-meld helped Luke when he took on 4 of the slayers while Jacen and Jaina took on 2 each. Or in his fight with Shimmrra in which Shimra controlled the gravity in the room.
But THAT isn't the fight that made Luke Uber. (well, the lightning thing kinda did, added anyway)
Luke's darkhole manipulation and planet cloaking is what comes out of that series on top.
His fight versus Thul, and then his "unable to be moved by black-hole in center of the galaxy" were his top feats in DN.
I'll say this: in my mind, Sidious was also godlike in his force exploits.
However, at the end of the day, he wasn't skilled enough in the force to avoid being thrown down a freaking ventilation shaft.
You DO always refer to Luke's low-points, as though they somehow DAMAGE his more powerful moments.
You seem to think that godlike MUST include infallibility, but I disagree. I dont' think one has to prove himself again to be godlike in every possible situation.
Sidious for example, isn't diminshed in mind because of his rather ignamonious ending. He is still godlike, despite his lowpoint of falling down a ventilation shaft.