[Tenchi Muyo! Ryo-Ohki 1-3]
Can you make a good harem show?
So far this old (and once very popular) show is answering a question I've never bothered asking: can you make a good harem show? Well, it turns out you can. However, I don't think the way this show has done that so far is really repeatable.
A number of things stand out about this show. Firstly, the setting, which is a mish-mash of contemporary, fantastical and sci-fi. A fun mix, if pulled off well by a competent team, alternatively it could be a big mess if you did it poorly. So far they've managed to make it work by keeping these particular set-pieces (the shrine, the temple, the spaceship) fairly isolated from each other.
Having this variety of settings means the writers have a lot of freedom in terms of actually throwing out scenarios for the characters, rather than just the usual highschool crap. On top of that, the art and animation is pretty good, which I would expect from an OVA, but it's still unusual to see it at work in a harem piece. I'm not used to seeing gratuitous and enjoyable space action in any work these days, actually.
The characters and writing aren't amazing or anything, but neither are they terrible. They all seem to work out fairly well and that's more than I can say for most shows. It seems that they just had the ill-fate of all being re-written into every harem work ever.