Optimus's Swords

Optimus Prime used to have dual swords that could extend from his hands for melee combat.

"Darkness Rising, Part 4"
He used them to a devastating effect against an army of undead Terrorcons.

"Darkness Rising, Part 5"
He also used them against Megatron.

"Legacy"
Optimus later acquired the Star Saber which then served as his primary melee weapon.

"Rebellion"
When Optimus upgraded his body through the Forge of Solus Prime, he lost both of these swords, but gained new projectile weapons as replacements.