I'm pretty indifferent too, but I usually discover the anime before the manga, well, because I live in North America, and manga is hard to find. I also love music, and so watching anime gets me to listen to music that fits the situation.
In terms of art style and storyline? Well, the manga is obviously more detailed, and the storyline may seem a little rushed and unbalanced at times.
I still perfer anime, but manga is good with the art style, and story line, while anime is there for action, music, and just the fact that your favourite manga characters are talking and walking ^^