The Collaborative International Dictionary of English v.0.48:

Appreciative \Ap*pre"ci*a*tive\, a.
   Having or showing a just or ready appreciation or perception;
   as, an appreciative audience. -- Ap*pre"ci*a*tive*ly, adv.
   [1913 Webster]

WordNet (r) 3.0 (2006):

appreciative
    adj 1: feeling or expressive of gratitude; "was appreciative of
           his efforts"; "an appreciative word"
    2: having or showing appreciation or a favorable critical
       judgment or opinion; "appreciative of a beautiful landscape";
       "an appreciative laugh from the audience"

Moby Thesaurus II by Grady Ward, 1.0:

65 Moby Thesaurus words for "appreciative":
   acclamatory, accurate, acknowledging, admiring, alive to,
   appreciative of, apprised of, approbatory, awake to, aware of,
   behind the curtain, behind the scenes, beholden, cognizant of,
   commendatory, complimentary, conscious of, crediting, critical,
   delicate, differential, discriminate, discriminating,
   discriminative, distinctive, distinguishing, encomiastic,
   eulogistic, exact, fastidious, fine, flattering, grateful, hep to,
   in the know, in the secret, indebted to, informed of, laudatory,
   let into, mindful of, much obliged, nice, no stranger to, obliged,
   on to, panegyric, precise, privy to, refined, regardful,
   respectful, seized of, selective, sensible, sensible of,
   sensible to, sensitive, streetwise, subtle, tactful, thankful,
   undeceived, under obligation, wise to