As Jack99 said...
but IMC, Getting Raised from the Dead is a once in a lifetime happening and the ritual is not readily available. Maybe a handful in the world can cast it, and getting them to cast it will require at the very least a difficult quest by the other players.
..so it is in my campaign.
I play in two other campaigns though, and in one (in fact two nights ago) my favorite (4e) character died - not knocked out, but actually died.
The character is a favorite in the campaign and everyone seems to be all about getting him a rez. The DM is more than willing to allow it - in fact, we were going to skip the next scheduled game as I will be out of town, but now he says it's just good timing = he will run the game without me and it will be a game involving bringing my character back.
With that said, and despite him being my favorite character, I told him I was more than willing to let him go. That I would roll a new character because in letting him go it can give the campaign that feel that... if you die, you are gone, which I really like.
In allowing them to bring him back, you get the feeling that there is nothing to worry about in the campaign... you get knocked to zero? You will be back up after the encounter... you actually die? no biggie, you know you will get rezzed after a game. If it takes me losing my favorite character to instill a fear of death in the other players, I'm all about it
---edit---
We'll see what happens - he has kind of left it to me how I might come back, if at all.