1. The Big Boss (1971)
2. Fist of Fury (1972)
3. Way of the Dragon (1972)
4. Enter the Dragon (1973)
5. Game of Death (1978) (released posthumously, with much of the film completed by a stand-in after Bruce Lee's death)
Bonus:
* The Green Hornet (1966-1967) (TV series - Bruce Lee played Kato)
* Marlo and the Dragon (1972) (released in 1972 after Enter the Dragon, but filmed in 1971) - This movie was unfinished, with only 18 minutes of footage existing.
Note: Bruce Lee also directed "Way of the Dragon". He was also credited with directing "Game of Death", but it was mostly completed by a stand-in after his death.
If you're looking to watch Bruce Lee's films in order of production, the list would be:
1. The Green Hornet (TV series)
2. Marlo and the Dragon (unreleased)
3. The Big Boss
4. Fist of Fury
5. Way of the Dragon
6. Enter the Dragon
7. Game of Death (mostly completed posthumously)