The Unforgettable Fire is like some kind of... I dunno... opera? In a way? It's a massive journey. An unbelievably great song.
COBL... I like the spirit and sound and idea of it, it's just such a shame about the production. It's all there, it's just not sure what is supposed to drive it and define it.
Comparitively I don't think there's much there. Unforgettable Fire is a very complex song. COBL is a very simple one, that sounds more complicated then it is due to there being a lot going on and its pace. The Unforgettable Fire tells an amazing story. COBL is a nice little 'thank you' (which is fine, and great in it's own way), but certainly isn't a high point of Bonos writing. They're in different baskets. They're not trying to be the same thing, even if some of you can hear it in there, so really shouldn't be compared.
BUT on the personal opinion voting thing, Unforgettable Fire is in my Top 5 U2 songs and would be a must have on the tracklist of the U2: An Introduction CD that I would give someone. This is my favourite song of theirs from the 80's and in my opinion is one of the songs they can really hold up high throughout musical history and yell "FUCK! We are good!"City of Blinding Lights? Not even remotely close. It's an okay song that could have been better, but it is one of the 3 off the Bomb that I listen to semi-regularly. It feels good when driving. I'd like to see how it comes across live. It won't ever hold a place up there with the Unforgettable Fire level of songwriting though.