-Footnote.com is the most similar to Ancestry; they have the entire Revolutionary War pension files, a few Civil War Widows' Pensions files, and a number of databases that Ancestry doesn't have
-World Vital Records is just plain terrible; they have only a very small fraction of the records that Ancestry has; I tried the free trial and couldn't find anything at all; don't waste your time with it
-Find a Grave is free; it's a database of user-submitted cemetary records