There's a multi-step process to the ultimate best way to die. It goes something like this.
1. Acquire chair.
2. Acquire piano wire.
3. Acquire superglue. Not the usual garbage stuff they call superglue at the hobby store, I'm talking the industrial-grade stuff. Like the kind they use to patch holes in airplanes, or whatever. The stuff that's like one step removed from rubber cement, basically.
Arrange the chair and piano wire into the standard sad boy lineup - IE chair on the floor, MC on the chair, piano wire in the shape of a noose. Seems pretty standard, right? Wrong, because here's where it gets good.
Have the MC superglue his hands to the sides of his head and wait for the glue to completely dry before he kicks the chair out from under himself. The chair goes bye, and assuming the piano wire has been arranged properly, then it goes straight through the MC's neck. But because his hands have been superglued to his head, it looks like he's just pulled his head clean off by himself instead of hanging himself.
This way, your MC not only gets isekai'd, but he also gets to pull a postmortem prank on whoever finds him.