Well, I'm quite a fan of anime, and I've never really enjoyed cartoons. I find the top-quality japanese animes to contain excellent plot and character development, a strong storyline accompanied by the common oriental mystical "aura", and overall better graphic design and animations.
I prefer anime because the plot is typically more story-driven. An episode of a western cartoon is more of a one-act play, whereas an episode of an anime is a chapter typically in a book. This is not *always* true, but by-and-large anime is more like a story. I enjoy it for that aspect.
Now, if what I want is a quick reel of laughter, then I have to go with a western animation like family guy. Anime is rarely packed full of laughs like a western cartoon.
Anime of course.
Why?
Because it's very realistic, stories often are very awesome and interesting, drawing style is a lot better than cartoon's style.
Why not cartoon(western animation)?
Because very often plot is dumb(no offense), drawing is poor.
P.S. Some cartoons are very good by the way, Yasuragi. -=^.^=-
Would have to say I am Biased. Japanese animation is so much more in depth, the storyline, graphics, and overall time spent creating it(thier budget). With shows like Wolfs rain, Naruto, Rurouni Kenshin, Bleach, FMA, And many others. I hate to say it but nothing in western cartoon industry can touch it. Although I have to give major props to Nickelodeon for the Avatar series. The only issue I have with japanese animation is they draw things on and on at times. A classic example would be DBZ, DBZGT, and Naruto all with an average of 100+ episodes.(Naruto has 320 in the first year of the seris and 18 now in the new one) If you haven't watched much animation I would recomend Full metal alchemist, Wolf's Rain and Bleach.
Even Classics like Voltron, GI JOE, Scooby doo, and Transformers have very little to story line as they all have the same ending every episode. Graphics of them make me cringe till and I loved these cartoons. Avatar here is the only gem the western film industry have for the mass's that like anime.
With the release of Final Fantasy's Avent Childern and Spirit Within I see a big jump in animation quality very soon in both Western and Japanese animation.
Edited: Kozak on 23rd Jun, 2007 - 11:56pm
The difference in animation quality alone is not just in the character design, but also in the framing and the way some high quality japanese cartoons immitate the movement of cameras and experiment with viewpoint. Japanese cartoons are clearly much better. However, japanese animation is heavily influenced by American animation from the 50-60s, so both traditions have diverged from a common point.
I more prefer Japanese animation. I can't recall one Western animation that I have seen and kept watching. With Japanese animation, it's like stepping into a fantasy land, and enjoying everything that is going on. The stories aren't always reality-faced, but it is surely quite enjoyable. I'd choose a Japanese animation over a Western one any day.