Nadley [name]Zahara[/name] [name]Piper[/name] [name]Liv[/name] [name]Ever[/name] [name]Leighton[/name] [name]Petal[/name] [name]Tatum[/name] [name]Marlee[/name] [name]Vivienne[/name] [name]Blythe[/name] [name]Avery[/name] [name]Harley[/name] [name]Reese[/name] [name]Sienna[/name] [name]Kennedy[/name] [name]Hayden[/name] [name]Simone[/name]
Which ones are good and which are bad?
Nadley [name]Zahara[/name] [name]Piper[/name] [name]Liv[/name] [name]Ever[/name] [name]Leighton[/name] [name]Petal[/name] [name]Tatum[/name] [name]Marlee[/name] [name]Vivienne[/name] [name]Blythe[/name] [name]Avery[/name] [name]Harley[/name] [name]Reese[/name] [name]Sienna[/name] [name]Kennedy[/name] [name]Hayden[/name] [name]Simone[/name]
I like…
[name]Liv[/name]
[name]Ever[/name]
[name]Simone[/name]
[name]Blythe[/name]
I don’t like…
Nadley
[name]Leighton[/name]
[name]Zahara[/name]
[name]Avery[/name]
[name]Harley[/name]
[name]Marlee[/name]
The other’s are somewhere in the middle for me.
From your list, I really like [name]Vivienne[/name], [name]Blythe[/name], and [name]Simone[/name].
Good luck! 
I like the names [name]Liv[/name], [name]Ever[/name] and [name]Sienna[/name].
I dont really like the others, [name]Harley[/name] is not so bad but I prefer [name]Harlow[/name]
[name]Leighton[/name] is ok, reminds me of [name]Leighton[/name] Meester from Gossip girl or the tennis player [name]Hewitt[/name].
My favorites -
[name]Piper[/name]
[name]Liv[/name]
[name]Marlee[/name] (spelled [name]Marley[/name])
[name]Vivienne[/name]
[name]Simone[/name]
Nadley - too masculine, and sort of like [name]Natalie[/name] with a blocked nose.
[name]Zahara[/name] - Brangelina …
[name]Piper[/name] - the only -er name I actually like (probably because I was quite a Charmed fan when I was a teenager)
[name]Liv[/name] - as a nn for [name]Olivia[/name] (although [name]Olivia[/name] is very popular). I don’t think it can stand on it’s own (just my opinion)
[name]Ever[/name] - I’m not a fan of word names, especially those which fit in the ‘[name]Destiny[/name]’ category, as I’m afraid this does.
[name]Leighton[/name] - I’m not fan of surname names myself, but as they go this isn’t bad. [name]May[/name] become more popular in a couple of years because of the Gossip Girl actress.
[name]Petal[/name] - too cutesy
[name]Tatum[/name] - it doesn’t have a very nice sound … also, the first thing I thought of was [name]Channing[/name] [name]Tatum[/name], the actor. [name]How[/name] about [name]Tatiana[/name]?
[name]Marlee[/name] - I don’t really like.
[name]Vivienne[/name] - lovely, such a classic.
[name]Blythe[/name] - one of the only more masculine names that I like. In fact, I adore it - it has such a lovely flow.
[name]Avery[/name] - I’m not personally a fan, but it is like (but better than) [name]Ever[/name], which you said you liked.
[name]Harley[/name] - like the motorbike? I don’t think that’s a good image to have (I’ve nothing against motorbikes, it’s just not very neutral.) It might be the sort of name she would like to have as a teenager, but I’m not sure how well it would age.
[name]Reese[/name] - I prefer [name]Rhys[/name] (ree-ss) for a boy. Reminds me of [name]Reese[/name]'s Peanut Butter Cups, too.
[name]Sienna[/name] - lovely.
[name]Kennedy[/name] - too masculine.
[name]Hayden[/name] - I’m not fond of.
[name]Simone[/name] - I think this is a little dated, but I do quite like it. There is the ‘moan’ sound, though …
Names like [name]Petal[/name] :
[name]Poppy[/name]
[name]Tulip[/name]
[name]Violet[/name]
[name]Rosamund[/name] and other [name]Rose[/name] variants
[name]Daisy[/name]
[name]Padma[/name] - means lotus in [name]Indian[/name].
You might like [name]Briar[/name], too.
[name]Hi[/name] there. I don’t think there is such a thing as a “good” or “bad” name - there’s only what you like and what you don’t. One look around this board and you will see that preferences vary wildly from person to person 
. That being said, some of my own thoughts and preferences about the names you listed.
First thing that comes to mind is that many of these names are those of celebrities and/or celebrities’ babies. While this isn’t necessarily a bad thing, it often guarantees that the names will quickly become (or already are) quite popular. If doesn’t bother you, then more power to you - go for it! If it does bother you, you might want to seek out other, similar but distinct names.
My personal preferences for the names you mentioned:
*NADLEY: don’t care for the sound of this much.
*[name]ZAHARA[/name]: cool sound but definitely screams “[name]Brad[/name] and [name]Angelina[/name]'s little girl”
*[name]PIPER[/name]: [name]Love[/name] this. It’s cute and simple. Sounds like an independent little girl.
*[name]LIV[/name]: I do like the sound of this, and I like it more than the very popular [name]Olivia[/name].
*[name]EVER[/name]: [name]LOVE[/name] THIS! It’s probably my favorite of those you have listed. For me, I just like the sound, I don’t have the “[name]Destiny[/name]” association with this name that the previous poster does.
*[name]LEIGHTON[/name]: It has a very pretty sound, but to me it comes off as sort of “snobby.” Also for me has heavy duty Gossip Girl associations.
*[name]PETAL[/name]: this is my other fave of those you’ve listed. [name]Love[/name] it.
*[name]TATUM[/name]: I think this is really cute. I think it’s been around long enough that there’s not necessarily the immediate association with [name]Tatum[/name] O’[name]Neal[/name], and that the name stands on its own.
*[name]MARLEE[/name]: also cute. I prefer the [name]Marley[/name] spelling. But getting more popular.
*[name]VIVIENNE[/name]: pretty and classic, but again, I have the huge [name]Brad[/name] and [name]Angelina[/name] association.
*[name]BLYTHE[/name]: cool, classic.
*[name]AVERY[/name]: this one has gotten very popular for girls. I don’t care for it myself.
*[name]HARLEY[/name]: can’t help but think “…[name]Davidson[/name]” LOL. Also, to me the sound is kind of harsh.
*[name]REESE[/name]: Okay.
*[name]SIENNA[/name]: this has become so popular in the city I live, that I don’t like it as much as I used to. It has a lovely sound, however.
*[name]KENNEDY[/name]: I don’t like it for a girl. I don’t personally care for last name-first names for girls - or boys, for that matter.
*[name]HAYDEN[/name]: don’t like it for a girl - again, that last name as first name thing.
*[name]SIMONE[/name]: I like this!
Anyway, I support you in naming your baby whatever YOU want 
. Good luck!
Nadley: I think of the slang for testicles, unfortunately
[name]Zahara[/name]: [name]Sahara[/name] desert + [name]Angelina[/name] [name]Jolie[/name]. It’s still pretty cute to me, though.
[name]Piper[/name]: Distinctive, cool, and a little cutesy
[name]Liv[/name]: not my style but cool, pleasant and simple
[name]Ever[/name]: confusing and unnecessary when there are so many full names with similar sounds
[name]Leighton[/name]: I’m usually not a last name fan but this one’s very attractive
[name]Petal[/name]: sweet but difficult to take seriously on a grown woman
[name]Tatum[/name]: unique and strong but reminds me of potatoes, a little lumpy-sounding to me (could well be just a me thing)
[name]Marlee[/name]: not my style but cute–seems like a friendly, happy sort of name
[name]Vivienne[/name]: a little elaborate but certainly beautiful; I’m a big fan of V-names
[name]Blythe[/name]: cute, straightforward, strong, and unusual–I’m impressed
[name]Avery[/name]: cute
[name]Harley[/name]: too motorcycle for my taste
[name]Reese[/name]: I fear it has gone entirely to the girls but I still like it on both girls and boys–it just strikes me as stylish, strong, and sweet (the chocolate association doesn’t hurt)
[name]Sienna[/name]: a little trendy but very attractive
[name]Kennedy[/name]: it’s such a well-known, powerful, political last name in the states that I prefer it as a last name–that said, it has a nice sound
[name]Hayden[/name]: unless you’re a big fan of the composer, I would avoid this [name]Aidan[/name]-rhyming-mega-name
[name]Simone[/name]: one of my favorites–strong, attractive, familiar yet underused, classy, and maybe a little romantic
Nadley [name]Zahara[/name] [name]Piper[/name] [name]Liv[/name] [name]Ever[/name] [name]Leighton[/name] [name]Petal[/name] [name]Tatum[/name] [name]Marlee[/name] [name]Vivienne[/name] [name]Blythe[/name] [name]Avery[/name] [name]Harley[/name] [name]Reese[/name] [name]Sienna[/name] [name]Kennedy[/name] [name]Hayden[/name] [name]Simone[/name]
Which ones are good and which are bad?
I dont think any names are “good” or “bad”, it is just such a personal choice and we all have out reasons - unconscious or conscious - for liking or not liking particular names.
Having said that, you asked the question what do you think, so:
Sorry if this is not very positive, but you did ask!