Well, I'm going to pick one favorite because I refuse to not pick Mercury.
I will go with Mercury, Rockslide, Hellion, Surge, Prodigy, and Wind Dancer.
I debated Pixie, but left her out, mainly because her focus period came at the tail end of the series and she's been elevated so much more as a general X-Men character since it ended that I don't think of her as an Academy kid as much as the others.