what's style of push-up do you find most challenging?

right now I hate declined diamond push-ups

One hand push ups are the toughest. Can do 2-3 reps, thats all.

I love push ups with two swiss balls and feet on floor. Working toward a swiss ball under every contact point.

I imagine planche push ups will be the hardest, I have too much mass in my legs to balance for these I reckon.

Out of the ones I can do... probably one handed knuckle push ups. 

Right now I'm just doing the regular push up and that's hard to do. LOL But I'm doing the 10 push ups for 7 days and then 15 for 7 days and keep going up and up until I get use to it. I'm glad that I saw this on Facebook.

Definitely handstand pushups! My very favorite exercise. :)

I love tic tac toe push ups I learned from Airmen after they completed basic.  One of my favorites to add to a tough at home workout!

<p>The most challenging push up is trying to push myself up off the sofa! </p>

ANY push up for me as im a newbie is challenging LOL but i'll get there!!!

Hardest push-ups?  Superman Pushups.   If you don't have a good core.. get assistance ;)

Tic Tac Toe Push-ups start in normal position, push up, widen right arm push up, back to center push up, widen left arm push up, back to center push up, open arms wide front and back push up, back to center push up, reverse arms front and back push up.  TIC TAC TOE!

The clap push ups with legs raised to a height of 1 foot or more

One hand using just two fingers (index+thumb) is the one i am chasing down now!

The 90 degree push-up is the ultimate challenge!!!!

The core, the balance, stamina. the all body is working!

Check it out!!!

I'm such a novice - there are different types of push-ups?  Can you expand on the different types please?

I can do 10 standard, but 10 military style is a challenge 

for now diamond push-ups!