Added 02/17/07: Everybody's Got Something to Hide Except for Me and My Monkey, by Moritaka Chisato. If the title alone doesn't grab you, I don't know what will. This song is technically in English, but it's the heavy-accent English of most J-pop singers, and I think it belongs more in the J-pop genre than the English. I don't know if this song is from something, a commercial or a show or something, but I'd prefer to think not. I like the idea of some songwriter sitting around and saying, "Hmm. . . what do I think will be a good name for a pop song? Of course!"
Added 02/10/07: Manatsu no Kajitsu, by Southern All Stars. Two things to pay attention to on this song: First, note the additional passion the singer (Kuwata Keisuke) on the lines in English, and the positioning of those lines in the chorus. Two, note the changes in the final chorus, as not only are the notes higher than the previous choruses, but there are more of them. That flexibility yields a novelty that, rather than finishing with repetition, makes the ending the best part.