My top fav helpers are...
#4. Linebeck (Phantom Hourglass)
Well anybody who's played Phantom Hourglass would HAVE to include Linebeck! After all he's funny, cowardly, and just entertaining. Without him Link would be pretty much stranded on Mercay Island while Bellum sucks the world's life force clean not to mention he was pretty epic in the final fight (He fights off Bellum for a bit and then he gets possessed and becomes the final boss! How epic is that?!?!?!) and his obsession with treasure and the S.S. Linebeck (his ship) is just so cool!
#3. Elzo (Minish Cap)
Yes I've included Elzo. He was actually a pretty fun little sidekick what with his sarcasm and whatnot in addition to the wierd things he says (he says in one part of the game something about having an egg snack and losing it in Link's hair for instance). Not to mention he also was a sidekick you couldn't go without after all he allowed you to shrink to Minish size and back.
#2. Midna (Twilight Princess)
Okay so who could've played Twilight Princess and not think Midna is one of the best helpers ever?! Definately not me! Anyways Midna is funny and sarcastic and some of the gibberish she spurts (you know, the video game voice) is pretty funny. Not to mention she was a good part of the story, being the true Twilight Princess after all. And her help is really helpful too. After all she allows you to switch between wolf and hylian form at will, allows you to do a lot of cool stuff as a wolf, and even warp!
#1. Zelda (Spirit Tracks)
Okay so anybody who's played Spirit Tracks would have to be insane to not think Zelda's a cool sidekick. After all she accompanies you throughout your entire adventure even assisting in battle. She's ghostly so she can possess those evil, nasty, phantoms that prowl the Tower of Spirits and assist you by carrying you over lava, distracting other phantoms, hitting switches, accessing the inaccessable (to Link), and so much more. Not to mention, like all the sidekicks since Midna, she's a dynamic character who changes throughout the course of the game. She kicks phantasmal butt.