painterly is really good because you can customise it yourself, or if you're looking for something quicker you could download something like quandry. HD packs look amazing but you have to mod the game in order to use them and I don't fancy that either - have already spent time modding to get things like airplanes and you always end up having to remove stuff to be compatible with notch's updates.
or you could always download my terrain texture modification click on my name to see my uploads, there's a guide to making my terrain work too.
