I don't think that selfish is the right word. More like desperate. Odds are a person isn't particularly thinking of themselves, they just want the pain to end, the sadness to stop. I think that it's selfish of friends and family members of that person to try to make a suicide attempt about them. Clearly the person making the attempt (or successfully completing it) is/was extremely distressed. Odds are that, that person just didn't know what to do and/or was afraid to reach out.

I've had so much experience with this first hand. Let me just say, I have outright told my parents that I was feeling depressed and made a passing comment or two about wanting to die and was NOT taken seriously. In fact one of my family members pulled the, 'your problems aren't so bad, look what I have to deal with.' However this person meant it, it came off as extremely dismissive. And there is NOTHING more selfish than telling someone who is seeking comfort/reassurance that their problems aren't so bad and/or that yours are worse.
This happened a second time but with a different member of my family and I ended up having to be the one to talk them down and monitor them. It was anxiety inducing because, though I've talked internet friends out of suicide, I didn't know exactly how to handle it IRL. And it drove me crazy that everyone was 'too busy' to help.That's selfish.

Suicide isn't a good thing, but typically it isn't done to spite people. It's done for release. And in some cases, the person feels like they are a burden/unloved or that the world would be better off without them. The person thinks that they are being selfless.

Suicide victims need sympathy and respect, not disdain and ill words. And suicidal persons need compassion, care, and help not accusations and a stigma.

I don't agree the answer is that simple. The rationale behind someone's suicide will be multi-faceted. Using that consideration, I can not pick either of this options.

The mental health issues of an individual aren't their own selfish choices. And not everyone who is mentally unwell will take their lives. These issues are complex and 'selfishness' is a particularly damaging term to throw around the mentally unwell and suicidal people.
Some people may specifically ponder about how it will impact on others. There is a distorted (or even real) perception that their friends and family will be better off without them.
Families can feel as though suicide is a selfish act when they also, justifiably but also selfishly, think about how suicide impacts on them. It isn't wrong for families to muse like that, in fact its a normal response. However, that doesn't in itself make suicide an entirely selfish act. People don't choose suicide lightly. For everyone who kills themselves there is much, much more going on than a simple 'live or die' choice.

Ever heard of Romeo and Juliet? They did it not because they were selfish, but because they wanted to be together.

@ranty I agree