Girls:
Svetlana "
Sveta"- can't stand it mainly because Svet means sweat in Swedish
Tatiana- this is the best one on your list
Ivanna- ok
Ekaterina- the E makes it difficult to say
Nadezhda "
Nadia"- ok, I like the sound of it, not the spelling
Irina- ok
Boys:
Ilia- seems feminine to me
Aleksei- great name!
Innokenti /
Innokentiy- dislike a lot
Nikolai- very nice
Evgeni- ok