1.) Ringil: Sword of Fingolfin...face it Fingolfin and Ringil really handed it to Morgoth. He never came out again. That makes Ringil #1.
2.) Aranruth "King's Ire": Sword of my boy, Elu Thingol. Thingol is willing to part with any sword in his store but his own. A testimony to it's dopeness.
3.) Anglachel(Gurthang): The cursed sword of Beleg and Turin, crafted by the dark elf; Eol. A dread and dangerous sword. " There is malice in this sword. The dark heart of the smith still dwells in it. It will not love the hand it serves, neither will it abide with you long." Melian
4.) Anguirel: Eol's own sword. You know Eol made himself a nasty sword. So nasty, Maeglin made sure to steal it.
5.) Glamdring: Sword of Turgon, Sword of Gandalf. The Foe Hammer...'nuff said.
6.) Orcrist: Sword of Thorin. The Goblin Cleaver. A sword of Gondolin, and dreaded among orcs and goblins.
7.) Grond: Mace of Morgoth. The Hammer of the Underworld. I know it's not a sword, but I couldn't draw Ringil without drawing the weapon it matched against. It's not at the bottom of the list, but stands as a representative of the super heavy weight class of magical weapons.