Theoden, what you said is exactly what I first thought of when I read the title to this thread.
Elrond, among many other things, gave the things most important to him: his children, both of his sons and his only
precious daughter! But beyond these invaluable givings, he was involved in the
war of the Ring for as long as there has been a Ring. He was instumental in the battle when
the Ring was first taken from
Sauron, and he then tried (and very very nearly succeeded) to have it thrown into Orodruin the first time. Even before that he was fighting against Sauron and his forces, which is, if I remember correctly, how he ended up in
Rivendell. He led many
elves there and establised it as a base and haven against the dark forces. Not only that, but like
Galadriel (one of the despicable children of
Feanor...) he was a
Ring-bearer, and with that ring did much over the
ages to help preserve the good in
Middle-earth.
Then there's the previously-mentioned priceless aid to
Frodo and the Quest (before Frodo knew there was a Quest) when Elrond saved his life from the Wraiths and the wound he received from them. (Thanks in this also goes to
Glorfindel, who has done his share in the long war against the Ring and the Wraiths.)
Elrond's advice and wisdom, and all of his actions, have been very necessary in this long war. Except for maybe
Gandalf, nobody IMO did more in the long run against Sauron than Elrond. By contrast, aside from the Dark lords, nobody except for Feanor and his children, and maybe
Isildur with his selfish actions, have done more to cause hurt and pain to those who live in Middle-earth. That includes Galadriel, though it's true that she and
Celeborn did do much at times to fight against the dark forces. Still, when all is considered, Elrond by far in the winner in this debate. Nothing he did, that I know of, even compares to the evils that Feanor and his children did, so all of this is a HUGE stirke against Galadriel.