GH3 doesn't really have that much in the way of songs that are both challenging and fun. I'd pretty much narrow that list down to these:
Cliffs of Dover
Cult of Personality
Pride and Joy
The Metal
Black Magic Woman
Welcome to the Jungle
Impulse
Some songs in GH3 I really hate:
Raining Blood: Textbook artificial difficulty. Almost none of the charting in this song makes sense and it's just annoyingly hard, and that's coming from someone who nearly FCed it.
One: Really boring for a few minutes and then it has a stupidly hard solo that's actually charted faster than the notes are really played for the sake of artificial difficulty. Really unfun song to play.
Before I Forget: Holy s*** this song is murder on the wrists and for no other reason than for artificial difficulty.
Number of the Beast - Really awful 3-note chords.
Stricken - See above.
3's & 7's - See above.
The Way That It Ends - fhdsjghsjdhfsdjfh
Through the Fire and the Flames - Nothing needs to be said about how they vomited a ton of notes all over this one and called it good.