See the results of this poll: Which spelling do you prefer?
Respondents: 36 (This poll is closed)
- Brooklyn : 33 (92%)
- Brooklynn: 3 (8%)
I prefer [name_u]Brooklyn[/name_u]. I have had a soft spot for [name_u]Brooklyn[/name_u] since I was a teen. Funny thing is I have never liked [name_u]Brooke[/name_u], and though I like names that end in lyn, I do not care for [name_u]Lynn[/name_u]/[name_u]Lyn[/name_u]. Strange, I know.
I prefer the [name_u]Brooklyn[/name_u] spelling. It looks like one name. [name_f]Brooklynn[/name_f] looks like two names ([name_u]Brook[/name_u] and [name_u]Lynn[/name_u]) smooshed together. I don’t find either spelling more feminine. It’s a place so technically it’s gender neutral.
I prefer -lynn endings almost always purely out of aesthetics. I guess I like long names and feel the final end gives it some conclusion. I’m also personally not wild about [name_u]Brooklyn[/name_u]/[name_f]Brooklynn[/name_f], but see the appeal for some people 
[name_u]Brooklyn[/name_u] all the way. The NN looks weird with the OO, to me.
And in my head it’s purely a place name, so you might as well spell it right.
[name_u]Brooklyn[/name_u] is better, despite the best effort of the Beckhams to make the name unisex, it will always be a feminine name to me.
The extra n makes it a misspelling.
I agree with @mischa!
I’m going to be in the minority here and say I prefer [name_f]Brooklynn[/name_f]. [name_u]Brooklyn[/name_u] is not feminine at all.