Any time on a cruise is a good time. We did a 2-night coastal cruise last year (SFO-YVR) and really enjoyed it. Though if we didn't live at one end or the other, I'm not sure we would have flown to get it. We're planning on a 3-day or 4-day Mexican cruise our of LA or SD (a relatively short flight away), but have not yet found one that matches our schedule.