I'm gonna have to agree with anerph on this one, it's very difficult to find completely original works there days - and surely similarities between series isn't simply limited to anime, but is rampant throughout movies, music, and other sorts of media as well - among other things.
If you check out almost any new movie, it is bound to share some similarities to other movies - of course the extent to which it resembles a different movie varies.
You can even find the same things among popular books as well (i.e. Eragon and the whole Star Wars/LOTR similarities). A lot of it probably due to the sheer amount of media that has already been released that it is hard to be original without being completely obscure ... and unfortunately completely obscure works don't tend to be as well received. The most original movie I probably saw in the last few years was probably Waking Life ... and although it was good, it was pretty damn weird.
On a completely random note, what character is that as your avatar bobjoe? Seems familiar, but I just can't place it ...