This is a deep topic, and I've read so many different opinions and approach in this thread alone. 

Suicide, for me, is a sad thing. It's not a matter of being tragic or selfish, but it is a sad thing, for the many reasons that has been covered the replies before me.
I don't think any of us could really judge whether someone who suicide is a selfish person or not, as it depended on many factors. 

Although, to be honest, there is one kind of suicide case that I couldn't help but wanting to yell 'Stupid!' and 'Selfish!!' to the deceased. 
I saw in the news couple years back, of someone who committed suicide in his boarding house, leaving a short suicide that basically said: "I love you, xxxx."
Why do I say it was stupid? The person named in the letter didn't even know that the deceased liked her. He never told her anything about it, or even hinting about liking her. If I remember correctly, the deceased still had family members (parents or siblings) at the time. 
For case like this one... it's definitely tragic for the family, but I can't help thinking that it's a stupid reason for suicide, keeping in mind that he never once told her about his being attracted to her. 
PS: He wasn't even that close to her, she only saw him as a passing acquaintance.