The Collaborative International Dictionary of English v.0.48:

peppy \pep"py\ adj.
   Full of pep; spirited; bouncy[2]; as, the peppy and
   interesting talk.

   Syn: bouncing, bouncy, spirited, zippy.
        [WordNet 1.5]

Moby Thesaurus II by Grady Ward, 1.0:

71 Moby Thesaurus words for "peppy":
   active, activist, activistic, acute, aggressive, alert, alive,
   animate, animated, bouncing, bouncy, breezy, bright, brisk, bubbly,
   chipper, dynamic, ebullient, effervescent, energetic, enterprising,
   enthusiastic, forceful, forcible, frisky, full of go, full of life,
   full of pep, gay, go-go, hearty, impetuous, incisive, intense,
   keen, kinetic, live, lively, living, lusty, mercurial, mettlesome,
   militant, perky, pert, piquant, poignant, pungent, quicksilver,
   racy, robust, smacking, snappy, spanking, sparkling, spirited,
   sprightly, spry, strenuous, strong, take-charge, take-over,
   trenchant, vibrant, vigorous, vivacious, vivid, zestful, zesty,
   zingy, zippy