I totally love this stuff and have since I was a kid. I became addicted when I was in college - when the "internet" was discovered. It can consume hours....and it did. I developed my own three step internet genealogy rehab program (kidding). I think I've gotten most of my lines back to dead ends -- some in the 1500s, most to the 1700s, except for the dead ends.
French Canadian roots have been a challenge. Lots of people with the same name, and I don't know the birth location of my "lost dude," born 1820s in Canada or upstate NY. Unfortunately, he is the origin of my maiden name.
The most challenging was the Lithuanian side. Family said I would never find anything out about my g-grandmother, Dorothy Adams, b. about 1890 or so, in MD or WV, with "Russian" roots. Well, I did - shocked even myself. Adams = Adomaitis. Turns out, Dorothy married young (15 or so), and her mother had three marriages and family was huge....kinda dysfunctional, which could be why she never shared details with her son (my grandfather). But, I have not gotten farther back past her parents (b. 1850s-1860s, Mariampol, Suwalki, Lith) -- without spending lots of money for a private researcher in Poland/Lithuania. Darn! Maybe some day.
I've had a subscription to ancestry.com since the 1990s, but does anyone have a sub to the European ships part (like, the ships TO Europe). Dorothy's half-sister (Josepha Levanovich) went to the UK in the 1930s, would like to know why. I have her on a return ship, next to a Hollywood moviemaker that she later married (William Lawson Harris, father of John Derek!). Wonder if it was their "honeymoon" or something.