Jack Johnson is so mellow, great for a rainy day. I haven't listened to him in a long time, life in New York isn't as mellow as it was in Texas. So, maybe your personality just doesn't fit his style, mine doesn't anymore.
Also, his most famous tracks are from
Brushfire Fairytales which is his worst album, IMO. Inaudible Melodies, Sexy Plexi, and Bubble Toes are well known tracks from that album. They are very... Dave Matthew's Band-esque.
On and On and
In Between Dreams are much better albums, if you ask me. Much more low-key.
His melodies are quite simple, but that's part of why they are enjoyable for me. His lyrics are also simple, but still profound. His voice is very soothing and, you guessed it, simple.
He reminds me of Norah Jones in some ways (you better not hate her too

). I've always thought that her voice matched her music perfectly. All the elements of Jack Johnson and Norah Jones (melody, lyrics, vocals, etc.) fit together perfectly to create great songs.
Oh, and he's an environmentalist

. His tour buses run on biodiesel fuel. You gotta like that

.
_Emerson