The days I cannot go to the gym I do bodyweight exercises at home.
- Push-ups with one arm are a great replacement to the bench press
- Similarly, vertical push-ups for shoulders (sorry don't know the name in English) are good replacement for the military press
- For the legs... I just take advantage of living at the 11th floor. Adding some extra weight like a filled backpack does the job
- Abs: I do standard crunches, as well as static positions like the V and the L position
I also have a pullup bar in the garage, for the lats, but I guess it doesn't count as it is a machine.