If you feel the urge to see a Peter O'Toole movie, try Lawrence of Arabia or My Favorite Year. They are both better than The Lion in Winter.
If you feel the urge to see a movie about Henry II, try Becket ... it even has Peter O'Toole. It's not as good as the movies I mention above, but it's better than The Lion in Winter.
At one point in The Lion in Winter, Henry says, "There's a legend of a king called Lear, with whom I have a lot in common." He's not wrong, but, in case you hadn't noticed, James Goldman, who wrote The Lion in Winter, is not Shakespeare. If you feel the urge for similar dramas, watch any of the versions of King Lear out there. Anthony Hopkins stars in a new one I haven't seen, nor have I heard good things about it ... it runs under two hours, which should be right up my alley, but Lear needs the extra time, like Olivier's version that ran 2 1/2 hours. Hopkins is in his 80s, now ... you can't have a young Lear. Hopkins actually makes his feature film debut in The Lion in Winter, as Richard the Lionheart. If you feel the urge to watch a movie where Richard the Lionheart shows up, try The Adventures of Robin Hood (1938).
I could go on, but why bother? The truth is, The Lion in Winter is a perfectly satisfactory movie. Peter O'Toole yells a lot, Katharine Hepburn does Katharine Hepburn, there's even a James Bond connection (Timothy Dalton also made his film debut in this one). The movie was nominated for seven Oscars and won three (Hepburn, adapted screenplay, and score, by John Barry ... another 007 connection!), because it's the kind of movie that got Oscar nominations in those days. (Hepburn actually tied with Barbra Streisand, which I think is still the only time this has happened.) It was nominated for Best Picture but lost to Oliver!, a film I like that has seen its reputation fall over the years. Still, you know the drill ... if you feel the urge to watch an Oscar-nominated Best Picture of 1968, try Oliver!.