Ah I didn't say it's the best film though! (though of course I see my mistake after revisiting the thread title, but, meh...it's all subjective really.)
There are films I would certainly rate above it in terms of story or acting or of course direction, however City is one of these rare films that is so full of imagination and detail, much like Nightmare Before Christmas, that every time you watch it you notice something you hadn't noticed before.
I'm a very visual person. I like to treat my eyes as much as my visceral and intellectual self, probably moreso to be fair...and City is one of those films I can watch countless times and still chuckle at the clones or the old guy pretending to be Santa but scaring kids out of their wits. The chaos theory montage. The brain in a jar. The siamese twin gang-leader. It's just so fucking incredibly lush!
I did rate and prefer it to Deli to be honest although I say Deli when I was much younger and have only half-watched it again since. I never got that epic feel from it though.