Felix is one of those ancient but nontraditional names for boys that have come into favor over the past few decades, a favorite of parents who want a masculine name with history and heft that breaks ranks with the standard Franks and Freds. Felix is also an international darling, ranking in the Top 100 in several European and English-speaking countries.

Otto is cool again. Long a quintessential Old Man Name, Otto has been promoted to trending darling of adventurous baby namers.

Astrid has been a Scandinavian royal name since the tenth century, and many people associated it with the Swedish author of the Pippi Longstocking stories, Astrid Lindgren. Astrid is derived from the name Ástríðr, which is made up of the Old Norse elements that mean "god" and "beautiful."

Hugo, the Latin form of Hugh, has more heft and energy than the original -- and of course we love names that end (or begin, for that matter) with an o. This one is especially appealing because it's backed up by lots of solid history and European style.

Emma has now been among the top girl names in the United States for several years, claiming the Number 1 crown in 2008 and again from 2015 to 2018 before dropping back to second place.

Elise is one of those golden names that stylish but not TOO popular. Its appeal is due in large part to its French flair and to the love for El-names in general.

Alexander has been in a Top 25 boys' name in the US for 30 years now. But namers are still attracted to its imposing historic pedigree.

Helena is one of those classic names that just misses making the US Top 1000 girl names for its entire history, falling off for a single year in 1992. Since then it's been drifting lazily up the charts, and makes a perfect choice if you want a name that both fits in and stands out.

A classic in its native Scandinavia, Axel has a cool rock 'n' roll flavor in the US, thanks to Guns N' Roses' Axl Rose (born William). With its distinctive letter 'x', it has an effortlessly cool vibe about it, and is currently growing in popularity.

Louisa, a quaint but strong vintage name, might feel fresher in English speaking countries than old favorite Louise, just as Diana and Julia have more energy than Diane and Julie at the moment. Part of this might just be that Louisa has never been so popular as Louise, so it makes a familiar but distinctive option alongside Eloise, Lucy, Luna, and Lucia.

Greta is an Old World name long tied to the iconic Garbo, but now synonymous with environmental activism.

Eva is a simple, classic Hebrew name for girls that recently slipped out of the US Top 100 for the first time in more than a decade. Pronounced either like her more popular sister Ava or less popular sister Eve, Eva is one of the elite group of girl names that mean life.

Heidi became known — and popular — via the 1880 eponymous children's classic by Swiss writer Johanna Spyri and, despite decades of American Heidis of all sizes, shapes, and personalities, the name seems permanently tethered to that spunky little girl on the Alpine mountaintop in the book and Shirley Temple movie.

A concise choice with a hint of chic, Sabine is the French, Dutch, and German form of the Latin Sabina. While it has never charted in the US, Sabine saw a slight increase in use in recent data, with 107 babies given the name (compared to 70 called Sabina).

Alexandra fell out of the Top 100 for the first time since 1983 in 2015 but is still a popular choice. Strong, tasteful, and elegant, Alexandra remains a chic modern classic with a solid historic pedigree.

Alina has been drifting up the US popularity charts since the early 1980s, and now sits in in the Top 200. But Alina's real strength is in its international flexibility: The name ranks highly in a wide range of European, English speaking, and Latin American countries.

The name Christian has fallen a bit from its 90's and 00's heights, but it's still quite popular. Once considered overly pious, Christian is now seen as making a bold statement of faith by some, while also having secular appeal for others. Christian's enduring popularity may be influenced by such celebrities as Christian Slater and Christian Bale, not to mention the fashion world's Dior, Lacroix, Louboutin and Audigier.

This name once seemed a bit grand and pompous for an American baby boy, but a significant number of parents are now preferring it as a substantial platform for the nickname Max, among them Jennifer Lopez and Marc Anthony, who chose it for their twin son.

Lost in limbo for decades and decades, Elsa now stands a good chance of following along in the progression from Emma to Ella to Etta, thanks to the ice queen heroine who "Let It Go" in the wildly popular Disney movie Frozen. The name shot all the up to Number 286 (its highest ranking since the 1890s) in the year after the release of the movie, though it's now dropped back down the list in the US.

A saint's name with a noteworthy literary background, including uses by Shakespeare in Two Gentlemen of Verona and Much Ado About Nothing, by Ben Johnson, Walter Scott, Longfellow, D. H. Lawrence and Neil Gaiman. In real life, her two most well known representatives are writer Ursula Le Guin and actress Ursula Andress. In literature, there is also Ursula Iguaran, a key, long-lived character in Gabriel Garcia Marquez's major work, One Hundred Years of Solitude.