Exercises, that don't require a gym or special equipment

Hi all!

Let's start a thread about exercises you can do without a special equipment and without going to a gym.
Just post your favourite exercises.

Here are mine:

• - every variation of ab exercieses (crunches, reverse crunches etc.)
• - push ups
• - Lunges
• - trizeps push ups
• - wall push ups
• - bent-knee push ups
• - Jumping Jacks
• - squats
• - what else?