You list Nodame
Cantabile as a favorite in your profile but not here. Did she not like that? Have you seen the
sequels as well as the original series? If a dubbed version is preferable, the Animax release of the original series is streamed at
Crackle.
Usagi Drop ("Bunny Drop") was the first show to come to mind for me as well. As Sackett notes, it is no longer streaming at Crunchy after being licensed by
NISA. Subtitles only, though.
If you are looking for an adventure show, you should give
Seirei no Moribito a try. It features one of the best female leads in anime, Balsa the spear-wielding bodyguard.
Crunchyroll has the subtitled version, with a powerful acting performance by stage actress, Andou Mabuki. The DVDs are currently quite inexpensive at
Amazon though their stock is limited. It appears that Media Blasters has bumped the price for this show back up to the $50 range, still pretty reasonable for 26 episodes.
If you liked the "senpai romance" aspects of
Planetes and
Nodame, I'll add
Toshokan Sensou to the list. It follows a young woman who joins a group of armed librarians who defend the freedom to read from an opposing group of armed censors. She falls for the young solider who is in charge of her training. You'll need to search for the subs for the original TV series; there is also a movie version with subs out there.
Take a look at this post for a
lengthy list of recommendations with an emphasis on stories and characters that might appeal to more mature viewers.