For me both songs are a 10, they're special in their own way.
On one side, the winner, 'Smells Like Teen Spirit' describes what the word "epic" means in the modern world. It changed a generation, a way of thinking, it was a declaration of independence by one of the most controversial leaders in music. In that time people didn't understand that well Kurt's lyrics, but the raw and powerful emotion of the song told you there was something heavy going on with the guy, and I'm paraphrasing Butch Vig.
There are not a lot of moments like this in music and there are not so many people that can so single-handedly changed the world with music like Kurt Cobain.
The video, one of the few produced videos by Nirvana has a simple yet so powerful concept. Highlighting the ignored, the cleaning guy, the punk kids. Making a twist to the cheerleader image, everything about the video was memorable and mind-changing.
On the other side, we have 'We Found Love', a song written by Calvin Harris and catapulted to success by Rihanna, her vision, voice and performance, this song means a lot in today's modern pop culture.
For a part, it changed pop musically, after this song we could notice the latest pop hits using similar structure of the song, just like 'Smells' formula, quiet verses and loud choruses, 'We Found Love' uses the verse-chorus-musical breakdown structure which has popularized. It's ravy, powerful and put EDM on the map not just as a pop ingredient but as the genre itself in the charts.
The single, huge and fresh for more than a year, produced one of the most acclaimed videos of all time, currently up for a Grammy and winner of 'Video Of The Year' in the 2012's VMAs. The video was also imitated later by her peers. Rihanna always flirted with an edgy image, but how natural the video and performance looks and how it divorces from the sweet image of the typical pop girl turns Rihanna into full-fledged musican and artist.
Ok guys, for the ones who cared about this thread, it will resume right after the lag problems are resolved, it's very time consuming to do it with the lag.