Ok:
Smart Movement: Smart Movement adds swimming, climbing, flying and falling animations. It also lets you climb up to three blocks lots more.
Minecraft Thirst Mod: This mod lets you get thirsty in Minecraft. If you sprint, you lose 'water drops' and if you have none, you start to lose heal. For more info look it up on YouTube.
TooManyItems (TMI): Lets you spawn stuff and you get to switch between creative and survival modes.
Minecraft Comes Alive: Minecraft starts talking and villagers get to talk to you and you get to marry.
Weird and Wacky Creatures Mod: Adds LOTS of more creatures like camels, werewolves (so annoying!), rats, robots and more.
Zombie Fly Mod: You get to fly.