omg... finally a question 😭😭😭
actually this made me think a bit 🤔 bc i've only talked about three enstars characters when it comes to vocals

☆ anyway obvious top 1 is ritsu! i really love each and every part of his in every knights song :)) his voice is sooo nice and so soft and just sooo ughesh GIVE IT TO MEEE... also his voice in general is just really!!! really!!! good!!! i'd steal it if i could

the rest are in no particular order... don't ask me what the ranking is bc idfk either. i had a hard time answering this UGHEEAAAEHAAAAAAAA
i think i ended up also ranking by how much i like their voice in general...... so sorry
i'm not good at describing voices sorry

• hiyori! maybe an obvious and easy pick but come on he's voiced by natsuki hanae...
• jun!!! dude... his high note in majestic magic? everything. yes i love eve and their voices. how do they sound SO BEAUTIFUL
• ummm uhhhh LEOOOO TSUKINAGA THE MAN THE COMPOSER THE EVERYTHING!! nozomU MELODYYY
• i also love midori! i know he kinda has some laziness to his singing (THAT'S NOT THE APPROPRIATE TERM BUT YOU GET WHAT I MEAAANN) but i liked his parts in aisle be with you! also seishun emergency... his part with ritsu? yeah
• I ALMOST FORGOT... I ABSOLUTELY LOVE ADONIS' VOICE 😭😭😭 i don't listen to undead much but when i do i'm always liek 😊 <- this emoji whenever i hear his parts!!! like idk smth abt his voice is soooo... Strong? like. hearty or some shit idk

some honorable mentions!!! i think hiiro singing voice very good :) very strong... then there's trickstar!!! n the rest of knights ^_^ kasa's vocals in luminous crown were really good :}

honesltly this list is like. very subject to change because i haven't listened to Every Damn Enstars Song so... AND THERE'S BIAS 😭😭😭 anyways sorry for the long ass reply i think i could've just said those 5 characters and left it at that