The Collaborative International Dictionary of English v.0.48:

Sentimentality \Sen`ti*men*tal"i*ty\, n. [CF. F.
   sentimentalit['e].]
   The quality or state of being sentimental.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sentimentality
    n 1: falsely emotional in a maudlin way [syn: mawkishness,
         sentimentality, drippiness, mushiness, soupiness,
         sloppiness]
    2: extravagant or affected feeling or emotion

Moby Thesaurus II by Grady Ward, 1.0:

53 Moby Thesaurus words for "sentimentality":
   affection, affectionateness, amativeness, amorousness, bathos,
   bleeding heart, cloyingness, corn, corniness, demonstrativeness,
   ecstasy, emotionalism, enchantment, goatishness, goo, gushiness,
   hearts-and-flowers, horniness, lovelornness, lovesickness,
   maudlinness, mawkishness, mush, mushiness, namby-pamby,
   namby-pambyism, namby-pambyness, nostalgia, nostomania,
   oversentimentalism, oversentimentality, pathos, rapture,
   romanticism, sentiment, sentimentalism, sexiness, slop, sloppiness,
   slush, slushiness, soap opera, sob story, soppiness, stickiness,
   susceptibility, sweetness, sweetness and light, tackiness,
   tearfulness, tearjerker, tenderness, weepiness