Via Wonderland, I see that the web-based adventure game Bow Street Runner is complete, after growing in chapter-based installments for a while. A production of the UK's Channel 4, it's an interactive and deliciously lurid dramatization about the birth of the modern police force in 18th century London. It begins with your proto-cop sighing over a dandy who's gotten himself dead in a bad part of town, so off you go to interview the local prostitutes and drunks, and root through garbage troughs. I love it.
Its overall production quality is at least as good as any "CD-ROM game" one might have purchased 10 years ago, when many more companies were trying to turn a dollar by churning out the next big Myst-style hit. But in this case it's free and needs no installation, so I encourage you to give it a whirl if you like this sort of thing too.