The Collaborative International Dictionary of English v.0.48:

Cheery \Cheer"y\, a.
   Displaying evident cheerfulness; cheerful; lively; gay;
   bright; pleasant; as, a cheery person; a cheery hello.

   Syn: pleasant, sunny.
        [1913 Webster + WordNet 1.5]

              His cheery little study, where the sunshine
              glimmered so pleasantly.            --Hawthorne.
        [1913 Webster]

WordNet (r) 3.0 (2006):

cheery
    adj 1: bright and pleasant; promoting a feeling of cheer; "a
           cheery hello"; "a gay sunny room"; "a sunny smile" [syn:
           cheery, gay, sunny]

Moby Thesaurus II by Grady Ward, 1.0:

127 Moby Thesaurus words for "cheery":
   Leibnizian, affable, agreeable, amiable, amicable, animating,
   beaming, beatific, beatified, blessed, blissful, blithe,
   blithesome, bright, bright and sunny, capering, cheerful, cheering,
   chiliastic, chirk, chirping, chirpy, chirrupy, comfortable,
   compatible, complaisant, congenial, cordial, couleur de rose, cozy,
   dancing, desirable, dulcet, elated, en rapport, encouraging,
   enjoyable, enlivening, eupeptic, euphoric, exalted, exhilarated,
   exhilarating, fair, fair and pleasant, felicific, felicitous, fine,
   flushed, flushed with joy, friendly, gay, genial, glad, gladdening,
   gladsome, glowing, good, goodly, gracious, grateful, gratifying,
   happy, harmonious, heart-warming, heartening, high, homelike,
   homely, homey, homish, honeyed, hopeful, in good spirits,
   in high spirits, inspiring, inspiriting, intimate, invigorating,
   irrepressible, joyful, joyous, laughing, leaping, lightsome,
   likable, mellifluous, mellow, millenarian, millennialistic, nice,
   of good cheer, optimistic, peaceful, perfectibilitarian,
   perfectionist, plain, pleasant, pleasing, pleasurable,
   pleasure-giving, pleasureful, purring, radiant, rewarding, riant,
   rose-colored, roseate, rosy, sanguine, sanguineous, satisfying,
   simple, singing, smiling, smirking, snug, sparkling, starry-eyed,
   sunny, sweet, thrice happy, unpretending, upbeat, utopian, welcome,
   winsome