I just got SF3 a week ago (my first Star Force game), and it's pretty fun! The Noise system in particular is pretty interesting, and can lead to some very devastating combos. So I'm just curious at to what Noise(s) people prefer.
My personal favorite is Virgo, being that water is my preferred element. The Charge Shot is excellent, as it pierces obstacles and covers all 3 columns when used in the center. Combine this with Icestage and BreakSword/Burai, and you've got a pretty nice damage source. I usually add +IcePnl to keep the fun going as well. I'm considering trying out Cancer as well, as the Bubble Shot looks like it could be fun to use.
I tried Cygnus (my first one), and Float/Air Shoes is pretty nice to have. The only gripe I have with it is the sword-type weakness, as sword attacks are quite common, and keeping your noise level high could be a problem, especially in competitive play.