A slightly better ending for Rhaegar [SPOILERS MAIN]
I wish Rhaegar died after Elia and co. in books and he got to know of their deaths before his own death (the problem obviously is that Tywin won't join the rebels before he was sure that the loyalists had lost, in that case maybe Aerys burns them in his paranoia)
It wouldn't change much about the plot of the main books and would also make his death less tragic, he would atleast be happier in his dying moments...