Isabella was the most popular baby name for a girl born in Washington in 2009, while Isabel was the least popular (at least, among the 100 names listed), according to the state Department of Health. For boys, Alexander topped the list and Lincoln came in 100th. Isabella supplanted Olivia, the top girls’ name in 2008, while Alexander bested Ethan. The department lists popular baby names going back to 1980 on its website, www.doh.wa.gov. That year, the top two names were Jennifer and Michael.