I'm one of the few who chose anime.....I just enjoy hearing the seiyuu/VAs, and I like the background music that gets added to it. And sometimes the humour/romance gets put acroos much better too. Like In Fruits Basket - it always seems funnier to me in the anime than the manga. And in CCS, Syaoran's love for Sakura was much more carefully developed and drawn out.
However, manga is very good too, and in some cases better than the anime. But in my opinion, cases like these are not in the majority.