I want to try the best before stop playing MMORPG games?

Usually the best games you would have to pay for, that's why I recommend World of Warcraft so highly, it can keep you occupied and entertained for more then 2 years... But if you still aren't willing to pay for a great game like that, I recommend Lord of the Rings online, Dungeons and Dragons online, or Allods... You may need a good computer for those though...