On the days I do workout, I find myself doing chest and tris.. . Another big issue with that is, if you dont, that leads to muscular imbalances.. for me it lead to an injury from training too much chest and not evening out my back.
The chest muscles are a muscle group that should not be neglected in any. but many people think that working out the chest requires a trip to the gym.. Straighten your back so that your feet and your shoulders create a straight, rigid line.
An easy solution is to forget all about the bench and do your chest workout at home.. Use that saved time as you wish, but it would be a shame if some of it wasn't. Do all the reps of each move back to back (or with as little rest as possible), rest for. . people have been known to catch theirs on the box mid-rep. Not pretty.