The Collaborative International Dictionary of English v.0.48:

Egotistic \E`go*tis"tic\, Egotistical \E`go*tis"tic*al\, a.
   Addicted to, or manifesting, egotism; having an exaggerated
   view of one's own importance or good qualities.

   Syn: egotistic; narcissistic; self-loving; conceited; vain;
        self-important; opinionated.
        [1913 Webster + WordNet 1.5]

WordNet (r) 3.0 (2006):

egotistic
    adj 1: characteristic of those having an inflated idea of their
           own importance [syn: egotistic, egotistical,
           narcissistic, self-loving]
    2: characteristic of false pride; having an exaggerated sense of
       self-importance; "a conceited fool"; "an attitude of self-
       conceited arrogance"; "an egotistical disregard of others";
       "so swollen by victory that he was unfit for normal duty";
       "growing ever more swollen-headed and arbitrary"; "vain about
       her clothes" [syn: conceited, egotistic, egotistical,
       self-conceited, swollen, swollen-headed, vain]

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "egotistic":
   acquisitive, ambitious for self, autistic, boastful, careerist,
   cocky, conceited, egocentric, egocentristic, egoistic, egomaniacal,
   egotistical, grasping, greedy, individualistic, inflated,
   narcissan, narcissine, narcissistic, narcistic, personalistic,
   possessive, pretentious, privatistic, proud, puffed up, remote,
   self-absorbed, self-admiring, self-advancing, self-besot,
   self-centered, self-concerned, self-considerative, self-contained,
   self-devoted, self-esteeming, self-indulgent, self-interested,
   self-jealous, self-occupied, self-pleasing, self-satisfied,
   self-seeking, self-serving, self-sufficient, selfish, stuck-up