As of my last knowledge update in January 2023, several popular basketball games were available online, offering engaging and realistic experiences for basketball enthusiasts. However, the popularity of online games can change, and new releases may have emerged since then. Here are some of the highly regarded basketball games that were well-received:

NBA 2K Series:
The NBA 2K series is widely considered one of the best basketball simulation games. Known for its stunning graphics, realistic gameplay, and extensive career modes, NBA 2K has been a favorite among basketball fans for years. The series includes various editions with updated rosters and features.

Basketball Stars:
The basketball stars is an online multiplayer basketball game that allows players to compete in one-on-one or two-on-two matches. With realistic graphics and intuitive controls, it offers an immersive experience for players looking for quick and competitive basketball action.

Basketball Legends:
Basketball Legends is an arcade-style basketball game with a fun and cartoonish aesthetic. It features famous basketball players and offers both single-player and multiplayer modes. The game is known for its accessible gameplay and entertaining mechanics.

Basketball.IO:
Basketball.IO is an online multiplayer game that combines basketball with .io-style gameplay. It features simple controls, fast-paced matches, and a competitive environment where players strive to score points and climb the leaderboard.