Number 2 all the way.
Number one sounds okay, but it reminds me too much of Pico with the excessive drums. Numbers 3-5 sound cool, but they don't seem appropriate for front page Newgrounds because they sound too mysterious.
I pick No. 2 because it stays true to the classic music, yet has a hip, driving, energetic dance beat to it. It makes you wanna get up and get your freak on. It's also less "heavy" sounding than the current re-mix that's playing on the front page.
Number 2 all the way, baby!