WordNet (r) 3.0 (2006):

upstanding
    adj 1: meriting respect or esteem; "an upstanding member of the
           community" [syn: upstanding, solid]

Moby Thesaurus II by Grady Ward, 1.0:

68 Moby Thesaurus words for "upstanding":
   Christian, blameless, bolt upright, clean, creditable, decent,
   downright, erect, estimable, ethical, fair, full of integrity,
   good, high-minded, high-principled, highly respectable, honest,
   honorable, immaculate, inviolate, irreproachable, just,
   law-abiding, law-loving, law-revering, manly, moral, noble,
   principled, pure, raised, rampant, rearing, reputable, respectable,
   right, right-minded, righteous, spotless, stainless, stand-up,
   standing up, sterling, straight-up, true-dealing, true-devoted,
   true-disposing, true-souled, true-spirited, truehearted,
   unblemished, uncorrupt, uncorrupted, undefiled, unimpeachable,
   unspotted, unstained, unsullied, untarnished, upended, upraised,
   upreared, upright, uprighteous, vertical, virtuous, worthy,
   yeomanly