Here are a few that can be done right at home:
1) Pushups (Traditional, with both feet on ground)
2) One-legged Pushups (traditional, but with one foot elevated off the ground)
3) Elevated Pushups (traditional pushups with feet elevated on a chair)
4) Dip Pushups (traditional pushups between 3 chairs - with each hand on a chair, and feet elevated onto another chair)
5) Door Chins (Wedge a thin book under a door to support door and stop door swinging. Place towel along top edge of door to rest hands and do chins on door, pulling yourself up along face of door – hands shoulder width apart)
6) Chair Chins (Face the backs of 2 chairs towards each other with a small towel draped over the back of each chair. Place a broomstick across both chair backs on each towel. Lie on ground between 2 chairs and hold broomstick, each hand holding close to each chairback. Elevate your feet onto a 3rd chair in front of you. Pull yourself up to horizontal position).
7) Crunches (feet on floor, knees bent, curling yourself up, hands next to sides)
8 ) Wallsit (stand upright, back against a wall, slide down wall with back touching until in a sitting position. Hold position, pushing back continuously into wall –slide back up and repeat)
9) Squats (Traditional squats, squatting down until top of legs are parallel to ground)
10) Chair Hamstrings (lie on floor, knees bent with feet on placed on seat part of chair. Push feet into seat using hamstrings and lift butt off floor as high as possible. Hold and lower)
11) Burpees (traditional burpee: 1 Repetition: From standing, drop to haunches, shoot legs out (to pushup position), shoot legs back (to haunched position), go back to standing.
12) Handstand Pushup (Optional Exercise; Very Advanved). Facing a wall, go into a handstand with feet touching wall (you should ideally be as close to the wall in the handstand position and also as straight as possible). Lower your head to the floor, but don’t let it touch and push up again. This is a very tough exercise if you are not used to it. At first, just maintain handstand position until arms are stronger to perform pushup.