worthwhile

worthwhile
    adj 1: sufficiently valuable to justify the investment of time
           or interest; "a worthwhile book"
    

51 Moby Thesaurus words for "worthwhile":
      advantageous, advisable, appropriate, banausic, becoming,
      befitting, breadwinning, congruous, convenient, decent, desirable,
      expedient, fat, favorable, feasible, felicitous, fit, fitten,
      fitting, fructuous, gainful, good, happy, likely, lucrative, meet,
      moneymaking, of value, opportune, paying, politic, productive,
      profitable, proper, recommendable, remunerative, rewarding, right,
      seasonable, seemly, sortable, suitable, timely, to be desired,
      useful, valuable, well-paying, well-spent, well-timed, wise,
      yielding a return