Spain? A guide...

HI,

My name is Pete and I'm fresh to this Thorn Tree thing. I'm a young Aussie, travelling around Europe for the second time. You may ask, why the hell, if he's been round Europe once, would he need advice. Well, the answer is simple, you can always do with a little more advice in life! I won't babble on, just to say that I have not yet been to the lovely country of Spain and am headin' there in early July. I'm already scheduled to visit San Sebastian and obviously Pamplona for the San Fermin (Running of the Bulls) Festival. I'm backpacking around (how else would you want to see Europe) and am travelling with friends and alone.
After Pamp's, I'd like to hit up a good portion of Spain and Southern France before smashing many drinks in the Greek Island's for the second time in 2 years! So...
Where is good to go in Spain, if you have 2-3 weeks to travel. I'm looking at using the coach and bus services more often than trains as they are less expensive I'm informed. I know it's a massively broad question and there are obvious places, but I'd love to hear opinion's and some of the more, inobvious places ppl have ventured and what they think is a positive route to take when considering the Spanish nation. I'm excited and willing to see anything and go anywhere. So don't be afraid to let me know what you think. I'm grateful for any and all responses to this post.

Enjoy your travel's and party like tmrrw doesn't exist!

~PT~