Very often, popular manga are adapted into an anime series but the contrary is also true.

Sometimes, some animes are disappointing, others are great.

I have read many manga and seen a lot of animes but my preference still remains towards the manga version most of the time.

For example, while I love the anime Tsubasa Reservoir Chionicle, I still prefer the eponym manga. The same could be said for Nodame Cantabile too.

Manga is (almost) always better. I think a reason for that is that my imagination does a better job filling the space between drawings.

Couldn't say it better...

It depends ... though, mostly I prefer the manga. Anime, generally, doesn't give off the same 'vibes' that manga gives ... maybe it's due to a less attention to emotions or characters and more to the action ... generally I find this problem in shounen, such as Naruto - no doubt I like the anime the most :)

I prefer the manga generally over anime, although I do like anime as well. One of the reasons I prefer the manga is because you get to see the original artwork in its true form, and also you can imagine the characters' "voices " in your head! Manga is also a lot cheaper (most of the time) and contains a lot of emotions in it!