Ancalagon
Dusty Dragon
I've always held that "getting rid of" an artifact (for campaign purposes, anyway) is generally not that hard if the party gets creative about it. Stash it in an impenetrable vault, toss it in a bottomless hole, banish it to somewhere else, break it in some cinematically interesting fashion, not entirely undoable.
Actually destroying one so that it doesn't just reappear somewhere else, get reassembled or otherwise come back to haunt the campaign world again (if not the party themselves) in X number of years/centuries isn't anywhere near as easy.
The original goal was to toss it in the gate and stop worrying about it. Then one player got clever...