Knightonline!! , no more =)
This is a discussion on Which is your favorite online game? within the Flash Games forums, part of the Off Topic category; Knightonline!! , no more =)...
If it is about choosing favorite online game, I would say it is bingo games, since I feel more connected with these games than any other ones. Most of the time I play these games at http://onlinebingo3.co.uk. Yeah, I know that my choice is quite different from other members here.