WTF? It's like a new thread like this pops up every day!
The thing is, a game that was a 95% two years ago may just be an 85% today. Standards change. If Super Mario Bros. 1 released today, it wouldn't be considered one of the greatest games of all time. Killzone was a 91% back when. Halo is an 87%, now. If we could go back in time and release Halo 4 back in 2009 (or whatever), it would dominate. Nothing is immune to time.