Neither, actually. I'd rather live to slice up others. But if it were inevitable, a knife ripping open my belly. But first, my nuts cut off so I could crush them with my teeth, and my cock cut off and rammed down my throat. All done in front of a mirror so I could watch my guts falling out and dangling from my eviscerated belly.
Stabbed, bare-chest, through my heart, after a sweaty and lengthy fight, finally pinned down. My hands around his wrist and he inches the blade closer to my bare chest.
I'm grunting and struggling, heart pounding against my sternum so hard, my killer can see each forceful and rapid beat at my lower left pec. He edges the blade to point at the visible pounding under my left pec. I feel the tip of his blade prick the skin of my bare chest, visible heartbeat pounding under his serrated blade, trickle of my blood trails down my body, over my abs and twirls around my outie belly-button. I feel the blade tear into my flesh and with one powerful jam, my killer drives his knife through my pec muscle, I feel my ribs break, and finally I feel the beating of my own heart against the cold steel in my chest.
Either one, but first - my killer places his hand on my chest and feels my heart pounding forcefully and rapidly. My hands are tied behind my back, he holds the ropes around my wrists, holds me while he digs his fingers into the spaces between my ribs, I can feel my own heart beating against his hand. Then he tosses me to the ground, and pulls his weapon, drops his britches, and grabs his large, hard cock. As he stroked, he stabs or shoots me right through my heart. The last thing I feel is a load of hot cum hit my lean belly.
Stabbed, i suppose. I'd want to watch my belly sliced open, or my pecs sliced off. Wanna see the warm blood. Feel it running down my skin. See exposed gut or muscle...my inner self.
Head blown open by a bullet, brains splattered, would look great, but I'd be the only one who couldn't enjoy seeing it.
So, yeah, stabbing. I'd get to see myself mutilated and bloodied. Maybe I'd get to jack off to it and die happy, albeit painfully.