Let's have a comparison of our finalists. Pros are reasons why I want to pick this one, Cons are reasons against picking it. Time is a seperate category because its not really a con, but it does impact my decison to watch it. Other is for notes and things that don't fit in the rest of the categories.

Title Pros Cons Time Other
Sailor Moon - The magical girl show. - Probably not the best animation
- Have to watch it subbed
-200 episodes total
- 1st arc is 46 episodes
Lots of death, none of it sticks (this probably doesn't apply to the baddies, I'm guessing). I don't know much about the premise.
Card Captor Sakura - The other magical girl series
- I like the premise
- um, there's no transformations? I don't know enough really find any cons - 70 episodes I've had conlicting opinions on it. (Beware of paraphrasing) Is it a 'MG classic', or 'not very representative of MGs'?
Madoka Magica - the reason I started this thread in the first place - I started this thread to find some other MG shows 14 episodes, IIRC
Futari Pretty Cure Fairly classic MG, I'm told I know nothing about it 49 episodes
Heartcatch Precure - I've seen the opening and liked it.
- Precure in general looks good
- It's got a very twee opening 49 episodes

Any information to help flesh out these choices is very much welcome, especially how much I can cut them down by. (That's more of a psychological thing. If I tell myself that I only need to watch 15 episodes, its much easier to start a series than if I have to watch 50. If it's not terrible, I'll probably see the whole series)
As somebody was kind enough to link me to the Heartcatch Opening, I did a practice Let's Watch!
Spoiler: I decided to keep the title spelling...

Letís watch Petty cur Heatcatch opening!
- Three seconds in and this is ridiculously twee. Pastel stars? Hearts? Children cheering? I used to be a brony and this is a bit much for me.
- So we have Bluegirl and Pinkgirl who are catching a heart. They recline into each other in a sisterly way. Pinkgirl seems to be the older sister, but Bluegirl appeared first, which suggests that she is the main character. Edit: Pinkgirl appeared first. Oops.
- They are replaced by two stupidly cute critters (they appeared earlier, but I didn't note it as it was so quick) and then replaced by Bluemagicgirl and Pinkmagicgirl, and then replaced by the title. I didnít get to check if the Magicgirls look like the normalgirls, but they appear to be the same age as each other.
- The Japanese title has Heartcatch precure written in English underneath it. At least I know Iím watching the right thing. There are children shouting something in Japanese, is it a catchphrase or the showís title?
- We then cut to Pinkgirl and Bluegirl in uniform, walking (presumably to school) and having a conversation we canít hear. Bluegirl seems to be explaining something, with the usual anime exaggerations. Pinkgirl communicates her frustrations in kind.
- Cut to one of the cutethings, waving its bum in my face. Twerking mascots, what next? Oh, itís some kind of marshmallow machine next.
- Thereís a face shot of some dark-haired girl in a more detailed style. She looks older than the sisters, maybe old enough to be a woman. She looks quietly sad. And then thereís a long-distance shot of a girl standing on a really big tree with pink clouds (Edit: probably sakura petals, which suggests a tragic story) around. She has the same long, flowing hair as Darkgirl, so it might be her.
- Now we meet a girl with short brown hair in a school uniform. Some faces fade in behind her and then a girl with a camcorder barges into shot. No, Videogirl, weíre taking the video. Oh, youíre zooming in on Pinkgirl and Bluegirl, who are embarrassed by the attention and run away, chased by Videogirl and a collection of finger puppets. The art style is now like cardboard cutouts.
- The Cutethings jump past the camera and then Bluegirl and Pinkgirl have apparently escaped. They share a giggle. Aww. Also the artís changed again.
- Transformation sequence! It looks like Bluemagicgirl and Pinkmagicgirl are Bluegirl and Pinkgirl. I should have paid attention to the differences in the Cutethings as they seem to belong to each girl.
- Quick montage through the Villains! We have red guy with sword and two friends whose faces I didnít see, a man and a woman in white who seem to have an angel theme, a dark haired lady with a purple background, a red hair decoration, and who needs some antiglare spray for her eyes.
- Bluemagicgirl and Pinkmagicgirl are fighting strange skeleton-doll things. They also seem to be powering up. The art style and enemies remind me of Soul Eater, but cuter. Then Bluegirl M(agic) goes all dragonball on them. Scream, big explosion, no more cute minions.
- Big shadowy monster appears with a big gust of wind and the sisters look worried, then pull out their auras and act like theyíll attack. They charge through a rain of lasers, fly up and then ram the monster while the BGM kids chant cheerfully.
- Monster explodes after the usual pause, then we get a panel of the sisters with the earth in the background. The song shouts koniichwa, which I think is a greeting/enquiry of health.

Ok, I need a bit more practice Watching things. Openings are hard because they have a lot of rapid cuts, so I have to note the changes every few seconds. Maybe an actual episode might be easier to comment on.
Anyway, thanks for your support. Would you be interested in a proper Let's Watch?