oftentimes, a game's bugs and glitches can offer even more enjoyment than the game itself, because of the degree of freedom they can allow along with the satisfaction of discovering something completely new.

so what are your favourites?
the glitches in kotor2 were also pretty satisfying. there were a couple of areas where an infinite number of enemies could be spawned, yielding infinite experience, as well as glitches for cloning lightsabers (crystals and all) and placing an infinite number of crystals inside a single lightsaber. being ludicrously overpowered is always fun.

here's another slightly amusing thing i found just now. remember that hole in the ceiling at the beginning of amnesia? here's what it looks like from above:

Super Metroid glitches were quite interesting at times too.



On the calc side, I remember the following (there's also a calc game glitches/walkthroughs/secrets section on Omni) from my games

-Metroid II: Expansion Set - Skipping Lower Staria and Boss 2 in Easy mode by going through Lower Inferno lava rooms without Varia Suit. It was also possible to stop lava from rising during the escape sequence in Easy mode by reaching the lava rising room (the exiting it on the other side) before you die, but it was very hard.

-Illusiat 3 experience stacking glitch - when an enemy gave more than 1 level-up worth of experience. And the final boss glitch that causes the battle (and game) to end earlier than supposed under certain circumstances.

-Zelda DLQ skipping switch exploit - Error in map design allowing you to skip a small portion of the 2nd dungeon.

-Illusiat 11 missing Legend Weapon battle terrain - For the optional battle against Legend Weapon in Chapter 5, there's no assigned battle terrain sprite. If you recently re-installed the game and had previously saved progress in Chapter 5, an error would occur if entering that battle. Otherwise, the terrain of the previous battle would be used.