Can't believe I forgot one of the most famous cases that's been followed/argued for 33+ years. Jeffrey MacDonald (NC). Convicted in 1979 for killing his pregnant wife and 2 young daughters in 1970 and has been serving a life sentence. Was the subject of a famous book by Joe McGinnis and that book was made into a TV Movie starring Gary Cole.
Yep, he's had people arguing his innocence ever since, to no avail. And his case was long before there was DNA testing available. In that case there was a lot of blood evidence. Each of the victims and MacDonald had different blood types, so investigators were able to determine who was where in the apt based on blood type. MacDonald's story didn't match the blood evidence.
I'm fascinated by that case. I remember the house being boarded up still in the late 80s. I loved Fatal Vision (both the book and movie). Here is a great site for that case:
http://www.thejeffreymacdonaldcase.com/
Note: The site has everything from the case. Be careful if you go searching around on it. It has crime scene photos and autopsy photos as well. It's heartbreaking.