I'm definitely recognizing some of these names, and others are on my to-watch list, and still others I haven't yet seen the name of. If I had to make a list of some of my favorite ecchi-yuri anime, let's see what I can add to not overlap with you guys...
>Here's where I'd put Maria-sama ga Miteru, except it's not an ecchi, but just as a light-hearted slice-of-life with some shoujo ai elements, it's worth a mention
>Kanamemo
>Simoun (I actually own the entire box set collection of this anime on DVD)
>Rin: Daughters of Mnemosyne (ofc)
Also just for the record, the ED for Candy Boy is addictive as f---.