You've got some awesome stuff on your list, so excuse me if I jump all over several of them, lol...
Rurouni Kenshin - My main reaction at the mention of these movies (as well as the manga and most of the anime) is just sheer squee, lol. The movies are so good-- drama and action and romance and a bit of comedy; the acting, direction, cinematography, fight choreography, music, costumes, set designs... everything is just perfect. If you're a fan of the manga, the story is definitely compressed and in the latter two movies, changed quite a bit, but it works anyway. It doesn't matter. SO SO SO good. XD
Nobuta wo Produce - I'm not huge into high school stories, but this went well beyond that. What seems to be a friendship story is actually more about personal growth, with a sprinkling of some kind of paranormal/magic/something over the whole thing. It's become one of my favorite shows, and I don't hesitate to recommend it to anyone.
Love Shuffle, Last Cinderella, Summer Nude - Three of my favorite romantic-themed dramas! I'm actually rewatching Love Shuffle as I write this, lol, which is so much fun and absolutely my favorite romance show. So many of the pairings throughout the shuffle would've been perfectly wonderful, and I wouldn't have minded if it had ended differently, even though I love the actual ending. :D Last Cinderella took a little bit to grow on me, but I adored it by the end, and the performances are most of why that's the case. I just recently watched Summer Nude, and saw a lot of criticism about the show and the acting, but I actually really enjoyed it. I think it's slightly more realistic in some ways than other romance-themed shows, which I found appealing, and I'm also a fan of most of the cast, which probably had something to do with it, as well.
Biblia Koshodou no Jiken Techou - This is a standard favorite of mine! I'd describe it as "quiet", even peaceful for the most part, which seems unusual for a mystery series. The stories are personal and usually sweet, and I came away from most episodes feeling calm and wishing I could go to the bookshop. :) Also, it's a very different role for Goriki Ayame than others I've seen her in.
Bloody Monday - EXCELLENT suspense with solid stakes. Both seasons consist of one, overarching story (no standalone episodes), and are very difficult not to just marathon straight through. A+ performances by the cast.
Dias Police - This is primarily a suspense/drama, but with a lot of dark comedy and even some buddy comedy throughout. The episodes are bite-sized (only 24 minutes each) so it's a quick watch-- but I wish there were a lot more. Also short eps, in the dark comedy category, and something I thoroughly enjoyed was Mahoro Ekimae Bangaichi.
Mirai Nikki - This took a little bit to grow on me, too, in part because of the outlandish setup. However, it hooked me around ep 2 or 3 and this was another marathon session; I had no idea what to expect.
Bitter Blood, Tokyo DOGS - Bitter Blood was actually my first Jdrama after watching RuroKen, and is what started my addiction, lol. It's a nice spin on the buddy cop idea, and the interactions between the leads make it great. The main villain chews the scenery a bit, but don't let that put you off; it works and is worth sticking it out. Tokyo DOGS is a bit more standard as far as buddy-cop setups go, but the leads play off one another wonderfully.
Honorable mentions: Kurosagi, Heroine Disqualified, Bara no nai Hanaya - I enjoyed them all but wouldn't list them as favorites. Bara no nai Hanaya was especially good of the three. Nagareboshi wasn't my cup of tea; it was a bit too deep into melodrama for my liking, but that's just my personal taste. YMMV.
Arrgh. Sorry this is so long... I got carried away, but can't figure out what to cut from this. :P
