I wouldn't want a violent and painful end, because i want to enjoy my last day with all the troubles of the world lifted. I'd go out, do a few things i like to do, walk on the beach and listen to the waves crashing against the shore one last time, enjoy a nice meal, maybe catch my favorite movie. And then at night, sip on a sour tasting drink and slowly drift off to sleep, like any other night, just this time i wouldn't wake up in the morning. That sounds wonderful, truly liberating. I wouldn't even be sad, i'd have a smile on my face and a spring in my step. In fact, I might even just choose to live another day, and another... safe in the knowledge I could always sign off when I want.
With a violent end though, you're always going to be dreading going through that last moment, and worried about SI kicking in and not going through with it. You would never escape the things driving you to suicide in the first place.