Specifically for 0.3.14 (what some are calling the "pi" release) I nominate "SuperPI": http://www.techpowerup.com/downloads/36 ... _v1.5.html
A little Win32 utility that calculates PI!

Personally I also nominate Disasteroids 3D: http://www.lmnopc.com/disasteroids3d/
It's an OpenGL game but it runs decently on a fast CPU even though ReactOS uses software emulation. The sound also works well and isn't choppy.
Any other ideas? There have got to be some other small, simple, win32 games or things out there that aren't bundled with crapware (I was going to recommend Winzip but then I noticed how much crapware is bundled with the current one now - ill just stick with my old tiny 7.0, couldn't get 16.0 to run under ReactOS anyway)
BTW, since I am thinking about it, the downloaded URL for PuTTY needs to be updated, the current one is gone 404. There is a new version just released anyway.