Howrse, but you dont download it.
alicia online
Google flash games. You'll get quite alot of websites to play online games.
no
alicia online (korean but looks REALLY FUN) and star stable (you have to have microsoft for both)
There are The Sims Online and The Sims Carniva, both online Sims games that are similar to Animal Crossing.
Neopets and other similar games can be found online...
There is a game called Voyage century online. Still looking for good pirate games :)
Call of Duty!
Only world of warcraft.
Yes there are games similar to the DLC Quest that you can buy for the Xbox 360. You can find the similar games from game retailers such as game stop or online.
Pokecyrus.
You can play halo games online at addictinggames.com, where they have a wide variety of free games, and many of them are similar to halo. I think you would enjoy playing on that website.