Mikhailtech take a look at GameTap, an online gaming service offering 40-900+ game titles for free (or a small monthly fee).

More recently, GameTap changed its subscription model to include two free plans which allows access to a limited number of games. The "Visitor" plan allows anyone to visit the GameTap website and play a small number of games (about 40) which rotates every week without registration. The "Green" plan requires registration but gives users access to the GameTap Lite client and allows them to play a slightly larger library of games supported by pre-rolled ads. The "Deluxe" plan requires a credit card and a payment ranging from US$6.95 a month to US$9.95 a month based on how long you sign up for, but gives you access to all games as well as GameTap TV. Additionally, there are over 450 games which you can purchase through GameTap, similar to other online game purchases.

GameTap Online Gaming Service Review