What was Hamlet's famous "to be or not to be" speech about?
This speech is definitely about his moral struggle and indecisiveness.
Saying the speech is simply about "suicide" would be seriously not giving it enough credit. Hamlet is an extremely deep character and this speech really shows his confusion about the events to come.
"Whether 'tis nobler in the mind to suffer
The slings and arrows of outrageous fortune
Or to take arms against a sea of troubles,
And by opposing end them." He is weighing his options. Clearly the heaviness of his dead father's request is a burden on his shoulders and he doesn't know which way to turn.
"No more; and by a sleep to say we end
The heartache, and the thousand natural shocks
That flesh is heir to. " He contemplates death or suicide because, well, things are really terrible for him right now. He's got the task of revenge in his hands and his family life is utterly awful. These are signs of Hamlet's depression, which is so evident throughout this play.
"Thus conscience does make cowards of us all,
And thus the native hue of resolution
Is sicklied o'er with the pale cast of thought..."
This paragraph is an example of Hamlet's indecision. He admits that after thinking about it, his conscience tells him that this whole thing is too much of a bad thing. 'The native hue of resolution is sicklied o'er with the pale cast of thought', as in, the resolution (killing Claudius) is now seeming like a bad idea now that he's really thinking about it.
It's sort of a "Now that I'm giving it more thought, this whole thing is really kind of messy and I'm not sure if I'm ready to go through with this without more analysis of this process..." type speech. Hamlet really isn't sure what he wants to do.
He ends his speech by saying "- Soft you now!
The fair Ophelia!- Nymph, in thy orisons
Be all my sins rememb'red." Because Ophelia has just entered the room and he's telling himself to be quiet (soft you now!) and is getting 'in-character' for his scheme.
Hopefully that helped? Let me know if you have any more questions.