Here are a few of my oddballs - because they came to the U.S. (relatively) recently.
2nd Great Grandfather George Gibbs who came from Prince Edward Island and married Nina K. Ellingwood in 1884. I have little information about his family or what town they came from on PEI. Their daughter Annie married Ray Everett Cotton, Fern Lyndell Cotton married T. Richard Carter
4th Great Grandparents John & Ann (McClure) Williamson who came from Manorhamilton, County Leitrim, Ireland in the 1820s with two children and settled in Bethel, Maine. Daughter, Rebecca married Elias Mellen Carter. Their son Augustus Mellen Carter had a son Edward Mellen Carter who was my great-grandfather. Williamson isn't a typical Irish surname but Ancestry.com says it can be Northern English, Scottish or Northern Irish. Manorhamilton is at the very top of Ireland just before the border of Northern Ireland.
4th Great Grandfather Reverend Edward Millford Whittle who came from the South. He was born in Charleston, South Carolina in 1766 but there is evidence that he lived with his mother in Alexandria, Virginia before moving to New England and eventually to Maine. His parents are reported to be from Ireland but I have found no records to support that claim. Ancestry.com says most Whittles are from Lancashire, England. His daughter Martha married Moses Yates; their son Gilbert W. Yates was the father of my great grandfather, Estes Gilbert Yates.
4th Great Grandfather William Yates who came to New Hampshire around the time of the Revolution but where he came from is subject to debate - even among his children and grandchildren. The History of Paris by Howard Lapham says he came from Portsmouth, England to Boston and then to Maine. He met his wife in New Gloucester, Maine and then he can be traced from Hebron to Norway to Greenwood, Maine. He was a farmer and a Methodist preacher. His children and grandchildren contradict one another on many points from where he was born (Scotland or England) and whether his parents migrated with him and whether he was "bound out" as a boy to work for another farmer. William married Martha Morgan and had Moses Yates, the husband of Martha Whittle above.
These are my most recent immigrant ancestors. Researching outside my comfort zone of New England and researching outside the U.S. is challenging but it's like gambling (and about as addictive) where you know that most of the records you look at are not going to be "winners" but when you find a bit of information about your ancestor, no matter how small, it's like winning the lottery and it keeps you going. I feel like the more I find out, the more questions I have that I want to research...good luck everyone!
Thanks to Chris Dunham for posting these pictures of the gravestones of William and Martha Yates on the Maine Genealogy Network.