Saw episode 1 of the Chokotto Sister anime, hated it (love the manga). I didn't like the art directing (awful coloring), and didn't like the lack of fan-service. Are the DVDs any better?
Honestly, the only good (animated) ecchi series I've seen so far is To-Love Ru, which is incredibly mediocre as far as plot goes. But it's an ecchi series, so LOL PLOT.
Hell, I managed to fap to the OP, come to think of it.
later on in the series (episodes 6 and on I believe) they randomly throw nude scenes in. I have not watched the entire series yet. I must say it is a decent anime if you accept that this kind of series has little to no plot, you are watching it for the fanservice and "wish real life was like that" moments.
the dvds could have uncensored/extended scenes, although that is usually not much (see Kodomo no Jikan)
I must disagree about the "art directing", I liked the coloring. for another good ecchi/humor/lolicon series try "Kyo no go no ni" (Today in class 5-2). it is an ova series with 4 episodes out so far. really funny series.