Well, I certainly don't hate any of their songs... Hell, I hardly dislike any of them.
X Japan have a few different sounds, so what someone might consider their worst song, another might consider their best.
I've always felt like White Poem was kind of a filler, so I sometimes skip it. It's pretty, though...
At first I didn't like Endless Rain all too much because I thought it was cheese-rific, but it's really grown on me the last few months.
Awww, what's with all the hate on Easy Fight Rambling and Taiji songs? They're cheerier, yes, but god knows I want something fun and happy after listening to Yoshiki's depressing music. When "Des-per-ate Ang-el!!" comes on, it's a relief to hear something cheerful for once.
Uhm...
Phantom of Guilt is kind of lacking, I think, but it's still a killer song. Again, depends on your taste.