I find that Kurt Cobain was the voice of a generation in more than one way - not only because he had what can only be described as one of the most powerful, unique voices ever, but also because his music expressed what so many of us felt in the 90s - at least those of us that are in our late 20s or 30s today. Being an outsider, being depressed, being alive - they captured it, and in a way that not many others did. Kurt may be gone, but his voice lives on and the songs from Nevermind are still an influence in music and style today. Nirvana not only created music - they created expression. That is what art is all about to me.
I love Lithium because it's my go-to song when I'm angry, sad, upset, unsatisfied, or when I just need to feel something. All of Nirvana's songs are full of feeling something. In my opinion, much more so than many romantic and "heartfelt" pop songs.