Self-voting

[Yosarian2]

But to answer the original question, I think a pro-town player voting for themself is almost never a good idea, and I think it speaks to the "frustration" people have at being a "plain vanilla townie". But that's a whole different topic of discussion...

Unless it's a meta-game decision, like "if I only vote for myself when I'm mafia, it's a tip-off..."

Seriously, though, mostly it is done out of frustration, and that's not really good for the game, sure. I can understand people wanting to just conceed once they know they've lost, but mafia is not chess, there's a much greater human factor involved, and there's always a chance that people will change their minds.

[Yosarian2]

We almost reached a situation in NYPD mafia where I would have voted for myself. It would have been an endgame with

1 player from scum team A
1 player from scum team B
1 confirmed innocent
and me, a townie, but not confirmed as innocent

It was an open setup, and all players knew that there were exactly two scum left, one from each team. In this situation I'd have wanted to be lynched so the two scum would know who each other were, and would hopefully feel compelled to kill each other on the final night, yielding a town win.

Interesting, huh?

Very interesting, yes....
Of course, the mafia people could have just both targeted the last townie that night, killed him, then killed each other when only the two of them were left, leading to a mafia tie instead of a town win, but that would require them to trust each other, and whichever one backstabbed the other would win...

Heh...anyway, sounds like a good pro-town stratagy at that point.