Finally got round to watching the finale and while it was good I have one major issue. It was aired ages ago so I won't bother with spoiler tags but some slight book spoilers so if you are still to read them I'd avoid the rest of this post.
I really feel they messed up the whole Tyrion thing in the TV show. In the books when Tyrion was younger he met and fell in love with a peasant girl and got married to her until his father found out and made Jamie say she was a whore who he hired for Tyrion and then had all his guards rape her and then made Tyrion go last. Then when Jamie helps him escape he comes clean and says that she was never a whore and she was just a normal girl who really loved him. This betrayal is important as Tyrion and Jamie don't part on good terms with a hug like the TV show. Tyrion promises retribution on Jamie and lies saying he really did kill Joffrey to torment him. He then goes and strangles Shae for sleeping with his father and then confronts his father asking what happened to the girl he loved and his father says she went “wherever whores go" and then he kills him.
That story line for me is really important as he doesn't just kill his father because of Shae and for sentencing him to death but for taking away the girl who truly loved him. The TV show version just seemed rushed and like Tyrion just went to kill his father for the hell of it when really there was a whole lot of emotional context and it leaves Tyrion wondering of the happiness he could have had had his father not taken it away from him.