The Collaborative International Dictionary of English v.0.48:

Eventful \E*vent"ful\a.
   Full of, or rich in, events or incidents; as, an eventful
   journey; an eventful period of history; an eventful period of
   life.
   [1913 Webster]

WordNet (r) 3.0 (2006):

eventful
    adj 1: full of events or incidents; "the most exhausting and
           eventful day of my life" [ant: uneventful]
    2: having important issues or results; "the year's only really
       consequential legislation"; "an eventful decision" [syn:
       consequential, eventful]

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "eventful":
   active, bustling, busy, consequential, exciting, full,
   full of incident, important, interesting, lively, memorable,
   momentous, notable, noteworthy, phenomenal, signal, significant,
   stirring