I don't prefer one over the other if we're going solely by animation. To me, they're all cartoons.
Now, when it comes to story-telling or story lines, that's about the only way I'd take anime over most American-made stuff. They tend to have stories that are ongoing and actually have proper endings. Even as a kid, before I knew what the heck "anime" was, even though I was watching it and just didn't know it, this always bugged me. I like closure to a series.
Seems like in Japan, even the ratings aren't the best in the world, they would still play the series and it actually has an "ending episode". Can't say that for most of the stuff over here. It just ends.