[Ibrîniðilpathânezel]

It seems to me as if the question here is not who had stronger grounds for seeking revenge, but who would have been more likely, due to their nature, to act on it, given a real chance. Both Elrond and Galadriel have what I think are equally compelling reasons to want to see him defeated. But who would have directly taken revenge, when the opportunity presented itself? Elrond knew the danger of allowing the Ring to continue existing, and was potentially in a position to at least attempt its destruction at the end of the Second Age. Tolkien never tells us that Elrond ever had any strong desire to take the Ring, even to destroy it. He tried to persuade Isildur to do it, yes, but we aren't told that the thought of grabbing it himself ever entered Elrond's mind. I think that may well have been the point at which he was most vulnerable to the lure of the Ring, and from what we know, he didn't act on it, even in his thoughts.

Galadriel certainly did; it's spelled out for us quite clearly, not only in her words leading up to her refusal of it, but also in the fact that the Valar considered her refusal perhaps the most important thing she ever did in her resistance of the Enemy, as it signaled the rejection of the personal pride that had led her to leave Valinor against their injunction, and her refusal to return with the other exiles at the end of the First Age. Elrond is a loremaster and a healer; though he is master of Rivendell, he shows no desire to rule any greater realm, or to have political mastery over the lives of others. Galadriel, on the other hand, left Valinor because of her desire to have a realm to rule as her own; she is politically powerful because she sought that position, not because fate thrust it upon her. Their temperaments are quite different, and I think the matter of pride is a significant part of that difference. It would seem that it was not a mighty struggle for Elrond to reject the Ring, but it certainly was for Galadriel. All of which, I suppose, could mean that though both might well desire revenge against Sauron, Galadriel, I think, would be more likely to actively seek it.