For all the people who own Donkey Kong Country, there is a really funny glitch on the very first level which everyone should be able to do.
Step 1: Go to level 1, Jungle Hijinxes

Step 2: Play throughout the level until you come to the box that has the rhino in it.

Step 3: Hop onto Rambi and go back to the beginning of the level (P.S. you can play as Donkey Kong or Diddy Kong, but it's only funny if you play as Donkey Kong)

Step 4: Climb up to the tree house, but don't go inside.

Step 5: Hop across the 3 trees that are right next to the tree house.(P.S. you should still be on the Rambi)

Step 6: You should see an arrow of bananas that is pointing down. Jump up and land where it is pointing and a keg will pop out of the ground.

Step 7: Get off the Rambi. Grab the keg and walk towards the tree house while still holding the barrel.(P.S. MAKE SURE THAT THE RAMBI HASN'T DISAPPEARED OR ELSE YOU'LL HAVE TO RESTART THE LEVEL)

Step 8: Now here's the really tricky part. Throw the barrel at the tree house. It will bounce off and come rolling back. Jump up, and right as it is under you, PUSH AND HOLD Y and you'll land on it while it's still rolling. When you approach Rambi, while you're still holding Y, push B as you're right where the rhino is.

If you have completed all of this correctly, a glitch will have happened.
Here is a link to a Youtube video that shows a guy do it perfectly.

You don't need a hack or anything, anybody should be able to do it.