it depends what you like but the best ones are listed below:
Too many items mod
the Aether mod
the Iron Man mod
battle gear mod
Minecraft doesn't have an official best mod.
The best armor in that mod is Halite armor.
ore spawn or hexxit
Twilight sword
There many ways install this mod but the best way is the CSM installer.
a mod where you can fly a plane on minecraft so get it
Nope. You HAVE to download a minecraft mod to have it.
Mo Creatures is a modification (mod) for Minecraft. You can get this mod by downloading it from The Minecraft Forums.
One example of a superhero mod in Minecraft is Superheros Unlimited for version 1.6.4.
Just search in google 'Minecraft mod downloader'
You can get a mod to do just about ANYthing you want, just do a Yahoo/Google search for something like "minecraft mod".
The Ender Dragon is a part of Minecraft, not a mod. You probably need to update Minecraft.