What is your favorite, can be rewatched any time, love it to bits and pimp it to everyone series?
Mine is Revolutionary Girl Utena. Its 39 episodes of lesbian butt-kicking. Swords, a secret society or two, sexy cars, taboo relationships, even a cute monkey for a shoujo mascot.
This series also features the most gut-wrenching back stab in all of anime.
The ending is satisfying. It's not happy, but it's solid and has a ray of hope. The cycle ends.
The artwork is fairly stylistic, and the style has been carried over to several other anime (it was used in Fruits Basket.) Everyone is super shoujo skinny, of course. They also have gravity defying hair. Since the series is 1997 vintage, everything was done on cel, but the artwork is remarkably consistent and restrained throughout. They quality dips a little during the 3rd arc, and there is some recycled footage, but they made sure to save enough budget that the final four episodes are polished and perfect. The final episode does not roll credits in the beginning, and has a different ending.
The music is very memorable, and was released as 10 soundtracks, mostly piano (since that instrument plays a major part in one of the subplots.) The opening is catchy, and both endings are okay, if not particularly outstanding. Utena was done before the current industry standard of getting big names for op/ed music, so you will have never heard of the groups.
Grades from me:
Plot: A+
Artwork: A-
Music: A-
Occasionally naked lesbians: A++++++
Final Grade: A