I like short, interval cardio training using the triathlon modalities and alternating between events (swim, bike, run).
I enjoy adding in short circuit training sessions with either strength training using body weight, dumbbells or trx. Or high intensity, Tabata style plyometric sessions.
For pure enjoyment, I love long walk or hikes.
For strength training, I like high intensity strength circuits. It accomplishes a lot in a short amount of time! For cardiovascular training, I think a mix of steady state training (walking, running, etc) and intervals (sprints, tabata training, etc) are the most effective for overall fitness and health!