While there is no official online web-browser version of The Simpsons: Hit & Run
This community-built tool, hosted by Donut Team, acts as a modern wrapper for the original PC game. It provides: simpsons hit and run online emulator link
Pros:
This is the grey area. Emulators themselves are 100% legal (courts have ruled that they are fair use). However, downloading a ROM of The Simpsons: Hit & Run from an online emulator link is technically copyright infringement because you are bypassing the need to buy the game. While there is no official online web-browser version