Luke Skywalker is "clichéd" in the same way Seinfeld is. A lot of his progression from farmboy to hero only seems clichéd now because things that came AFTER Star Wars have copied the formula.
The whole point of Luke is to be the kind of character most of you seem to dislike him for being. He's nothing more than a simple farmboy who happens to know a crazy old war veteran at the beginning of A New Hope, and at the end of Return of the Jedi he's a war hero, ace pilot and master swordsman with nearly godlike powers (if the Expanded Universe is to be believed).
The original Star Wars trilogy is all about the transformation from one thing to another. The Empire taking over and asserting their power in A New Hope and Empire Strikes Back, only to finally fall in Return of the Jedi. The Rebellion turning from guerilla fighters with only a handful of ships at their disposal to a strong fighting force with a fleet capable of launching a full-scale assault on a heavily fortified Imperial world (Endor, and later in the EU, Coruscant). Vader transforms from an evil, heartless villain, to a father torn between his master and his son, to finally a hero, turning from the Dark Side to redeem himself and killing off Palpatine.
Luke's is the most obvious of these transformations and, in my opinion, the strongest one. So in short, I really like Luke Skywalker.
Besides, Mark Hamill is kind of hot.