Reincarnation would kind of (maybe) suck. Beyond the living forever aspect, it entails all sorts of horrors. Here's one.
You die, and suddenly you get the distinct feeling you've done this countless times before. You might be happy about it, or you might not be.
Perhaps you get a great psychedelic trip through the swirling shit of existence, perhaps even catching a nice view of an infinite radiant horizon while riding a roller coaster through a breathing vortex of computational geometry.
Time no longer operates like you're used to, now it's become something else entirely.
Through all this, you might still remember your last life, you might be trying to cling to it, even though you no longer have the capacity for holding memories, let alone thoughts. It wasn't so long ago, was it? Why is it so hard to remember? On some level, you keep repeating your name, the face of your mother, you can't stop.
But this isn't the first time this has happened. Existence isn't afraid to taunt you anymore, it isn't hiding behind the walls of a logical reality, no sir, mind and matter have met. It's the most ruthless, merciless creature there is.
At the end, you might note things seem to be coming to a climax, but what could it be? What haven't you seen?
Then, the mocking voices run eerily silent, and things go black
As the light blinds you, and the doctor pulls you out, you realize the travesty that has befallen you. You kick and scream, you want to tell them all the truth, but gone are the words, all you can do is flail clumsily and scream in a foreign tongue. You can still see it, standing there behind everyone, smirking. You've got to warn them...you've got to warn them...
...