Both are "Great" episodes, but I much prefer Catnap over Agent X. What works against Agent X is the fact that I've seen the episode too many times on TV, it's on, or at least it seems to me to be on more than any other episode, not that I watch the Garfield Show anymore (sadly), except to rate and review them as I am currently, or in the future, had previous done. Catnap on the other hand is a great episode and perhaps the best so far.
See also
Awards | FAQ | User Ratings | External Reviews | Metacritic Reviews