I’ve signed up for donation for dissection. One slight caveat is that the institution - in my case a medical school - can decline to take your body if you’ve died of something infectious or if it’s been too damaged, eg in a crash. If all goes well, they collect the body, and when they’re finished with it they have it cremated. Family can have the ashes if they want. There’s a nice memorial garden with the names of donors. It’s all free… I mean, this is the medical school where Burke and Hare sold their murder victims, so they’re quite grateful to get your corpse for nothing.