(So, musically speaking, my tastes must be pretty similar to French eco-hippies. Hm.)
I also have to say... my favorite J-rock band is quite definitely Last Alliance, who does the wonderful closing theme for the "Ouran Host Club" anime. I love the guitar riff in that song... very Johnny Marr... and their playing in general is so damn tight and snappy, with wonderful choruses and excellent vocal styings and a real knack for cranking out addictive post-punk. Who cares what they're singing? Who cares if their looks are... well... kinda non-pretty by J-Rock standards? They sound great.