My opinions on the champion-specific Eternals (well, some of the notable ones).
Some of the good ones:
Ashe: Enemy champions hit with a full stun Enchanted Crystal Arrow (R) Braum: Projectiles blocked with Unbreakable (E) Gangplank: Enemy champions hit with 2+ Powder Keg (E) chains Jinx: Full damage dealt to enemy champions with Super Mega Death Rocket! (R) Morde: Champions killed inside the Death Realm during Realm of Death (R) Shaco: Number of champions Backstabbed (P) Sylas: Kills within 5 seconds of damaging enemies with their own ultimate Taliyah: Champions hit by Unraveled Earth (E) after being shoved by Seismic Shove (W) Vayne: Enemy champions knocked into map and champion-generated terrain with Condemn (E) Vi: Champions hit by maximum range Vault Breaker (Q) Zoe: Enemy champions killed within 3 seconds of being slept by Sleepy Trouble Bubble (E)
The reason I like a lot of these, is because a lot are things that don't happen super often (so they're not just screen-clutter) and they require that you use the champs' abilities to their fullest potential to get them. For example, max-range Vi Q or Ashe/Jinx R's. I think it should be the same for hook champions, because hitting a max-range skillshot at all feels very good, and I think warrants an accomplishment much more than hitting the ability in the first place.
Here are some ones that I don't like: Aatrox: Sweet spot hits with The Darkin Blade (Q) Amumu: Multiple (2+) enemy champions hit by Curse of the Sad Mummy (R) Anivia: Double damage dealt to enemy champions with Frostbite (E) Azir: Multiple (2+) enemy champions hit with Emperor's Divide (R) Camille: Enemy champions hit with Hookshot (E) Diana: Lunar Rush (R) used on enemy champions affected by Moonlight Hecarim: Enemies feared by Onslaught of Shadows (R)
There are a lot more, but I don't want to list all of them, I think these get the point across. Things that regularly happen several (or dozens) of times per game are not good. Camille's I think is the worst. It's just unnecessary screen clutter whenever you hit an E, which is all the time. Also hitting 2+ champions with an AOE R seems cool enough, but it happens way too much. Most of the time you use Amumu, Hecarim, Azir, etc. R's, it's because you're hitting multiple people.
TL;DR: I like the accomplishments that make you THINK when using your champion, and I think they shouldn't happen more than several times per game, generally speaking.
(there are some contradictions I have in here but don't pay attention to that)
