I would like to try out some game demos on my DOS and Windows 98 PC before I take the time to hunt down these games. What are some great demos for 1990 to 2001? This also includes shareware games - anything legally downloadable (and still available online).

In particular can someone recommend some RTS games / demos. I like Red Alert, Age of Empires and city building games but seem to have trouble clicking with some games so a good demo would be useful!

I've tried things like NFS3 and Quake 3, doom...

Thanks!