Always the top spelling of the name; Neil peaked in the 1950s, but then enjoyed a second coming following the fame of such Neils as astronaut Armstrong and singers Sedaka, Diamond, and Young. Now semiretired.

Niall is pronounced nye-al--something like Neil, but this Irish spelling of the name makes it much more current and cool.

Nimbus is a word from nature for a type of cloud that has occasionally -- very occasionally -- been used for a human. But it's evocative and upbeat and certainly makes an intriguing and stylish nature name.

Always the less common spelling of Irish classic Neil, Neal has been on a fifty-year slide, and now doesn't even make the Top 1000. It has a streamlined, surnamey appeal in this spelling.

Nimbus is a new nature name that works for either gender and manages to be both familiar and unique. An evocative and daring nature name for the future.

An Irish classic for boys that has a streamlined, surnamey, unisex appeal in this spelling.

One of the boys' names that sounds fresher today for a girl. Second-best-spelling for boys, Neal, may work even better for girls.

While Niall -- pronounced as Neil or like the river Nile -- is conventionally a boys' name, it might theoretically work for girls.

Little-known name from the Old Testament.

Female form of Neal, now more popular in Ireland than its male counterpart.

Better to stick with the Neil spelling in the US, where the word "nil" also means "zero." But this is a Top Ten name in Catalonia.