>>2079793honestly, ecchi anime haven't been great lately.
HxH Gakuen just tried to be a safe-for-TV hentai (I need you to grope me so I'm strong enough to fight aliens every episode), which is pretty boring.
Shinmai maou no testament didn't know how to blend ecchi with story, so it kind of glued two different shows together (let's go out and fight bad guys and grope each other all day when we get home). It also had that safe-for-tv hentai thing going on, which is pretty boring (they threw in 'my curse is bothering me so I need you to grope me' as an afterthought. This is all of the ecchi this show has to offer).
Sin nanatsu no taizai is just laughable in every way.
If you want good ecchi anime, you'll have to go to the classics.
things like
Asa made Juugyo Chu (It's a one episode OVA, but it's definitely the best),
Ladies vs. Butlers,
Labyrinth of Flames,
Naujicaa Blitz Tactics,
Seikon no Qwaser (this one gets a little weird at times, though),
Kanokon,
Queen's Blade (seasons 1 and 2),
Sora no Otoshimono,
To Love-Ru Darkness,
maybe Highschool DxD but don't expect a lot of ecchi content from this one. It has it from time to time, but mostly doesn't attempt to blend ecchi and story. It attempts to make up for this by having an ecchi episode at some point.