Oguri Shun is definitely one of my favorites. He has a certain charm that really comes through in his acting. MatsuJun, of course, is awesome. Domyouji Tsukasa is one of the most memorable drama characters ever! Matsuda Shota is pretty good, too.
Horikita Maki's acting is very... subtle. Nothing about it really stands out, but for some rules that's perfect. I've only seen Toda Erika in Hana Yori Dango 2 and her character was absolutely infuriating, so I suppose she played it well, haha.
1 Litre of Tears IS truly fantastic. To be honest, most other dramas that deal with diseases simply fail to meet up to the standards that I set for myself after watching it.
Horikita Maki's acting is very... subtle. Nothing about it really stands out, but for some rules that's perfect. I've only seen Toda Erika in Hana Yori Dango 2 and her character was absolutely infuriating, so I suppose she played it well, haha.