Probably the best online game ever.
Made by Jim Bonacci (and some done by Jason Schymick), who also made the (less known) game Divine Intervention.

As described by Jim himself, the goal of Happy Wheels is "personal victory at any expense". And that's exactly what it is; you ride on a vehicle and your goal is to get to the finish. You can lose all your limbs, your son, your own vehicle, as long as you make it to the finish alive.

It's free, just go to the site and you can play it. It's on totaljerkface.com

However, there are way too many copied and unoriginal levels, like: Rope Swings, Kill Justin Bieber, Fight Chuck Norris, Ragdoll (also known as "fall down"), Jet Fall, Weapon Throw, "Rate 5 too see random glitch", Glass Fall, WWE, Saw: The Game, Arrow/Harpoon Run, Zombie Kill, Don't Move/Heart Donation, HOT FREE SEX, and the recently invented: "Made for UberHaxorNova".
It's recommended to not play these at all, and if you accidently click on one, you should rate 0.

It gets uploaded once per one or two months.

The only thing that will prevend you from playing it, is Headache Puppy, because he does not approve of repetitive refreshing.

The act of extreme masturbation. You must "knock one out" whilst in close proximity to any of the following; Your mum, a nun, your boss, a member of parliament, George Michael. A person with capabilities to act upon catching you mid self-abuse obvisouly ups the ante. Ejaculation must be reached before your danger wank target comes (no pun intended) to investigate. The higher the chances of being discovered with one's pants down, pulling one's war face is obviously where the danger comes from. The more danger involved the harder (or softer) it is to complete the task in hand (snigger). The more dangerous the better. The chance of being arrested, pummeled by an angry father or having your hand severed by an arab's sabre means that you are a pro "Danger wanker."

A game that you can play user submitted games as well as pre made games.

Online flash game game made by Jim bonacci. He's making a sequel, but the original was made in the late 2000s. You need to make it to the finish line alive, and at any cost to your health. You can get your bike crushed, so crawl the way there.
No limbs, no problem. The captions in the image are edited in, and originally said by the video recorder.
It's available at totaljerkface.com (not a joke link for real)

A fun game but a little bit gory as your body parts can come off. It's fun to play with friends as well.