I just thought I'd add my 2 cents worth

. I haven't tried the other sites mentioned yet, but I have found Genes Reunited simple to use in terms of searching other's family trees etc. Last Sunday I started researching my husband's family tree, knowing only his father and grandfather's names and dates of death and nothing else. Within 4 hours I had his great grandmother's family line back to 1400's France, and within 3 days had his great grandfather's line back to 1640. A large part of this was helped by what I found on GR, and the help of the people I contacted that way. Yes, I had to subscribe to contact them. But, to me, it was worth it, as I got a lot of data that has set me off in the right direction and given me a big boost in this whole genes researching.
Of course, most of you are far, far more experienced than I, and would know better what works, and many of you I'm sure have helped others through this forum etc. However, I thought it only fair to have at least one favorable comment for Genes Reunited, as I have found them very useful.

Regards
Cynthia