I have already decided on my method (firearm), but as far as other methods that I have considered in the past, here are a list of them. '+' would indicate pros and '-' would indicate cons.
Firearms
+ Very high reliability provided one uses sufficient caliber/round and aim correctly (hitting the brainstem and what not).
+ Easy to use with minimal instruction and training (watch a few videos and practice dry firing)
+ Readily available in the US (doesn't apply for other countries or places with restrictive gun laws)
+ Assuming a successful attempt, death is instantaneous or close enough, thus pain would not even register (or very brief assuming one is unconscious immediately after pulling the trigger).
+ For those who want to leave a huge impression or send a strong message to the world, a bloody, violent end is one big "fuck you" to the world, to society, to government.
- Very messy and traumatic for those who find the body and the mess (blood and bio-matter)
- Difficult and can be expensive to obtain for some, depending on where one lives.
- If failed attempt and survived, one could end up as a vegetable, brain-dead, even worse than before.
Hanging
+ Can be reliable if one knows how to tie a noose or slipknot and use proper rope that supports one's weight (also making sure the structure can hold one's weight).
+ Much less messier than the firearm and most other methods.
+ Cheaper than other methods and more accessible in most parts of the world.
- Not every place/structure is suitable for hanging.
- Will require a significant amount of time (30 minutes or more to be certain) to die after passing out from lack of blood to the brain.
- Can be very painful and awful if failed, possibly resulting in permanent damage including being a vegetable.
- Requires more skill to make a noose, unless referring to partial.
- Also requires more skill and coordination to tie the noose correctly.
N
+ Peaceful death provided one has anti-emetics, take enough and have enough time to die.
+ Very reliable and potent to ensure death.
+ Not as traumatic as violent methods and what not.
- Not legal and high risk of getting intercepted by customs and authorities, resulting in loss of the product (at minimum) up to serious legal trouble such as prison sentence and what not (maximum).
- Similar to the previous point, high risk of getting scammed and losing potentially hundreds of dollars.
Jumping
+ Does not cost much to attempt aside from the costs of transportation or getting to an area that has a significant height (ledge, cliff, bridge, tall buildings, etc.).
+ Very high success rate especially at sufficient height, landing on the head and dying almost instantly.
- Not always accessible, depending on where one lives and also access to tall buildings' top floor is difficult to access.
- Requires a lot of courage to stand over a ledge and just jump.
- Failure will result in serious injuries and very likely permanent damage, including being paralyzed, vegetable, etc.
