They're basically just big fun adventure/space opera movies.

The problem with the prequels is that Lucas himself started taking them too seriously and tried to add a few adult/dramatic elements, and the charm of the originals was lost. But they were still actually quite fun in parts, and the third one - 'Revenge of the Sith' is pretty good.

Watch the legendary Jedi swordsman Mace Windu (said to have the best light-saber skills of all the Jedi) arrive with 3 other Jedi to arrest Palatine after collecting definite evidence he's a Sith.

Palatine's menacing line; 'It's treason then...' is a classic, and he's a wonderful villain. Watch him pull a hidden light-sabre and cut down the other 3 Jedi almost before they can react, and then Mace and Palatine are alone battling it out, Palatine pressing hard, Mace having to draw on all his skills to get the upper-hand. And then just when Mace looks like he's got it won, he's betrayed, and dies a literally electrifying death! Classic!