I'd have to say the Deltora Quest series, including shadow lands and dragons of deltora, although the first of the three is the best.
I never really read anything anymore, and when I do, I read stuff I already know (I don't know why, nostalgia maybe), and Deltora Quest was my favorite when I was a kid, so it gets read the most and is still my favorite.
The anime also isn't horrible. It's the only american fantasy series I've ever seen get turned into an anime. It wasn't completely made in english, but the few episodes at the end that aren't translated are starting off the shadowlands series, but they never made that into an anime so those few episodes offer nothing anyway.
Before I read Deltora, Parsifal's Page was my favorite. If I remember correctly it's part of a series as well, but it's the only book I've read from it.
EDIT: Turns out I was mistaken. Deltora's not an American fantasy series at all. It's an Australian fantasy series.