I'm a fan (and you should be too) because...

his music is infectious. you listen to it once, it's stuck in your head. and after three weeks max, you'll go and get his record. but even more. once you HAVE the record, it's never gonna leave your stereo again, simply because gavin's music ALWAYS fits. it cheers you up or it comforts you, you can dance along or daydream while listening to it. it just has so many different sides to it.
gavin is an amazing songwriter. his music is a classic mix of all the good things in pop, rock, and blues. strong melodies; poetic, yet witty lyrics and in combination, the music pours out of your speakers, flows right into your ears and occupates your heart.
same with gavin; he's a born entertainer. his voice gives you goosebumps. an when he sits down at the piano OR picks up the guitar, a happy feeling tickles in your stomach. he looks into the crowd, sees all of us getting weak in the knees, and smiles. that's when you start falling.
there is simply no way you could NOT be a fan after listening to gavin.