Online games/quizzes/challenges

[Bloxo]

Hello all,
Thought this was the more appropriate forum to post this

Some of us like to compete with other players, where the loser will get a forfeit...this adds an element of risk and challenge, can build a fun competitive spirit and plays well into a lot of the threads you see in the Dare section.

But I raise the question...what are good games/quizzes online to play against others?

For example, there is an easily accessible online Battleship game, you can find it with a simple google...

When I try to find other sites, a lot of the games require both people to be in the same room using the same computer, but most people on this site won't either know or live near other members.

Can anyone suggest websites with fun head to head or even group places to compete.

Places where you can challenge specific players?

Any suggestions welcome, hoping the combined knowledge of members on this site can help other players out there to find new resources for their challenges