Just after E3, Ubisoft announced that it would be giving away 7 PC gamers for free to commemorate the company's 30th anniversary. Things kicked off with the 2003 remake of Prince of Persia, which isn't a bad title to have in your library for the total price of bugger all. But this might be better.
This month's offering through the Ubi 30 club is the original Tom Clancy's Splinter Cell, which was released all the way back in 2002. It's not the remastered version that was released on PlayStation in 2010, but it's also free, so you can't complain too much.
Same deal as last month applies: if you want the free game, you'll have to have a Uplay account. Most people have one these days, but if you don't registering is easy enough.
Once you've got Splinter Cell downloaded, you might want to look at getting some widescreen support. This forum thread has some basic steps on editing the resolution and field of view for maximum comfort. There doesn't seem to be a great deal of modding love for the original Splinter Cell — Chaos Theory's a different story — but for something that's free, you can't complain too much. I'm just hoping it runs on Windows 10 without too much trouble.