Being a conservative, usually means being an optimist. Episodes 4-6 were uplifting victories while 1-3 were dark tragedies which is probably why you liked 4-6 better.
Actually, the "uplifting" parts of the series were some of the parts I liked the least. They were too forced. I like the dark parts of the story, probably because these are the more dramatic portions of the series. "Empire" especially. I liked a lot of the eps. 2 and 3 dealing with Anikan becoming Vader because it had the same dark edge to it.
I enjoyed the original "Star Wars", but Lucas kind of made the Empire tough, and Han Solo really was (originally) a bad guy. Parts of "Jedi" were dark, but too much was muppets and teddy bears. "Phantom Menace" was a waste, because it was all fluffy and cotton candy.