There are a lot of manga featuring tits, what kind are you looking for? Since you specified "ecchi," are you trying to avoid hentai? What do you not like about hentai, so we can know what to avoid in the ecchi series we recommend?
I'm assuming you're avoiding hentai, gay shit, untranslated series and non-japanese stuff. Sadly, MU categorizes some kimchi garbage as manga though, if it was published in Japan. So we can't avoid Kill Time Communication-published trash like Lim Dall-Young shit. But other than that...
https://www.mangaupdates.com/series.html?category=Nudity_Borderline%2BH&exclude_genre=Hentai_Shounen%2BAi_Yaoi&filter=some_releases&type=manga&perpage=50
If you just want a show to tease your cock for eternity watch to Love Ru
Wouldn't this belong on /r/?
