There's a lot of great Kid Icarus items that could work great in Smash Bros.
I would love to see various weapons and weapon upgrades from Zelda and Metroid.
Seriously, a bomb bag item, and a bow and arrow with different types of arrow (regular, fire arrows that burn foes, ice that free foes, and light arrows that do massive damage), a ball and chain, a ALTTP hammer, an ice beam, a super screw attack (like in Super Metroid and Metroid Fusion), and a Dark World teleporter (where you got to the Dark World and eff people up in the real world like in ALTTP) would be awesome.
Also, the shoe from Super Mario Bros. 3. That shoe was my best friend as a kid!
Edit: Lucario's weight class is about where it should be. He could use a bit more weight in the next smash. He only weighs around 170 pounds. Mewtwo, on the other hand, weighs 270 pounds, despite weighing about as much as Peach in Melee! /fail