Minecraft 1.6

Potion of night vision: total blackout

Mobs visually sinking through solid blocks

3rd person view reverts to 1st person view if head inside a block (corner a one block wide tunnel in a minecart, ride on a horse through a block, piston...)

Mob heads darker or lighter on the left side

Powered pistons drop as items in creative

Ghost boats

Misaligned textures on south and east faces for non-full blocks

Fall damage is ignored for a couple of seconds when reloading into LAN or singleplayer worlds

Most text boxes / chat / scroll bars revert when the window changes size, fullscreen mode is toggled, or fullscreened game is tabbed into

Villagers ignore data tags in trading

Two zombies pushing eachother away when attempting to break (villager) wooden doors.

Zombies and Skeletons don't burn on slabs

Failing to place blocks in creative mode causes an animation

Sky/lighting doesn't get darker during a thunderstorm

'Drowning' meter doesn't reset when there's a block overhead, in running water

Extreme Performance Issues

Eating a food item / drinking potion / curing zombie / feeding animal has a chance of also consuming a second food item / potion without any animation

Clouds are transparent when you are above/in them but not when you're underneath them.

Black Lighting under overhangs

Walking on blocks less than 1 block tall placed on ice, slime blocks or honey blocks acts like walking on ice, slime block or honey blocks directly

Anvil GUI truncating long item names and showing garbage at the end

Player's and Horses head while riding having strange behaviour when looking at the skin in the inventory

Ghost End Portal in The End / Missing layer with AMD/ATI graphics cards

Dropped items bounce on stairs, cauldrons, carpets and full / locked hoppers

Mobs going out of fenced areas/suffocate in blocks when loading chunks

Inconsistent door texture

Players can place and remove arbitrary blocks in Adventure mode, breaking pre-1.4.2 maps

Potion of night vision: total blackout

Mobs visually sinking through solid blocks

3rd person view reverts to 1st person view if head inside a block (corner a one block wide tunnel in a minecart, ride on a horse through a block, piston...)

Mob heads darker or lighter on the left side

Powered pistons drop as items in creative

Ghost boats

Misaligned textures on south and east faces for non-full blocks

Fall damage is ignored for a couple of seconds when reloading into LAN or singleplayer worlds

Most text boxes / chat / scroll bars revert when the window changes size, fullscreen mode is toggled, or fullscreened game is tabbed into

Villagers ignore data tags in trading

Two zombies pushing eachother away when attempting to break (villager) wooden doors.

Zombies and Skeletons don't burn on slabs

Failing to place blocks in creative mode causes an animation

Sky/lighting doesn't get darker during a thunderstorm

'Drowning' meter doesn't reset when there's a block overhead, in running water

Extreme Performance Issues

Eating a food item / drinking potion / curing zombie / feeding animal has a chance of also consuming a second food item / potion without any animation

Clouds are transparent when you are above/in them but not when you're underneath them.

Black Lighting under overhangs

Walking on blocks less than 1 block tall placed on ice, slime blocks or honey blocks acts like walking on ice, slime block or honey blocks directly

Anvil GUI truncating long item names and showing garbage at the end

Player's and Horses head while riding having strange behaviour when looking at the skin in the inventory

Ghost End Portal in The End / Missing layer with AMD/ATI graphics cards

Dropped items bounce on stairs, cauldrons, carpets and full / locked hoppers

Mobs going out of fenced areas/suffocate in blocks when loading chunks

Inconsistent door texture

Players can place and remove arbitrary blocks in Adventure mode, breaking pre-1.4.2 maps