Yeah umm.....let me think
#1 is what I'de expect from the portal, that fast pace, but I really don't care for it.
#2 is a moree catchy version of #1, but it still doesn't interest me.
#3 has kind of an eerie tone to it, scary like, but it's just too slow for the portal, even though i really love the tune, really catchy.
#4 is an improved version of #3, I reallyyy enjoy that one, It's still not much of a portal song though.
#5 Has a strange trance like feeling, like a good song for a car commercial, don't know why but it just does.
MY FINAL VOTE IS FOR #4. I CAN ADJUST TO IT BEING ON THE PORTAL AND I REALLY THINK IT'S THE BEST ONE HERE.