Just make sure you lift really heavy weight and smash it down on the floor when you're done. That way, even if the noise is annoying to your neighbors, they are too afraid of you to say something.
In all seriousness, exercises that don't require a lot of moving around are going to be your best bet. Pushups, squats, overhead presses... a lot of weight lifting exercises like that. If it's cardio, then you might have to stick with things like mountain climbers, or find another place to exercise... like the park.