Clodagh - I don't like this, it looks and sounds ugly to me.
April - love it
Avril - less keen though not really sure why
Heather - it's ok, sounds a bit dated to me.
Kirsten - like it. Unusual nowadays.
Jane - bit plain. It's a middle name to me
Leila - really like it
Amara - like it
Eilidh - love it
Maren - not keen. Never met one though
Juliet - love it
Aifric - never heard this and can't pronounce it but it seems a bit Saxon Overlord ish to me! Like Ethelred and Wulfric!
Étain - also not sure how this is pronounced
RÃona - very pretty, I like it
Ailbhe - don't know the pronunciation of this either (feeling thick now!)
Lois - it's ok
Lara - love it
Serena - not keen but it's ok
Cliona - to rhyme with Fiona? Never heard it but think I like it
Rachel - it's ok
Mariela - not keen
Lena - like it
Liadain - not sure how to say this
Saoirse - it's ok
Elena - like it
SÃofra - pretty, never heard it before
Róise - not sure how to say it
Aphra - really love it and very unusual
Aurelia - quite like it. A bit fancy maybe.
My top three, in order, would be Aphra, Juliet and Lara.
My favourite Irish name is Sorcha. Also like Ciara, Carys, Niamh, Caoimhe, Aoife, Kayleigh and Fionnhuala.
Less Celtic (well some probably are but more anglicised) but in a similar vein to some of your other names:
Aria, Astrid, Ayla, Asha, Alexa, Bronte, Cecily, Dulcie, Darcey, Danica, Eden, Erin, Effie, Etta, Ebony, Fallon, Farrah, Giselle, Harper, Iris, Jade, Kyla, Kyra, Lyla, Lyra, Livia, Mala, Mila, Maya, Nyah, Nia, Noelle, Piper, Quinn, Romy, Rowan, Ramona, Rowena, Saffron, Sorrel, Sadie, Skye, Taryn, Thea, Verity, Zia, Zara