Well if you’re going for the “Mediterranean experience” I’d just go to Barcelona. Also there’s a handy night train that goes [most of the way] there.

4 nights?

I’d say split them between Madrid and Barcelona.   2 nights each.  Optional daytrip from Madrid: Segovia, Toledo, or even Sevilla thanks to the swift AVE.
 
Consider adding a 5th night.

I’m not a huge fan of Madrid, so I would opt for some time in Barcelona.  That being said, it’s a personal bias, so do some research and see if it clicks with you.

I’m having a hard time choosing between Madrid or Barcelona. I have 5 days so I could do both, but AFAIK the high speed train connecting Madrid and Barcelona is not complete yet.

@Phil101:This guy has high definition videos of places in both Madrid and Barcelona if you’re interested. http://www.vimeo.com/478234

Thanks for the tips guys. How about Ibiza?? Anyone been there? Worth going there if I’m by myself and on a schedule where I would have to sacrifice Madrid or Barcelona?

I dunno…Ibiza looks nice… if it was me, I wouldn’t even do Madrid. Everyone I know that has been there had something stolen or got beaten up… not to scare you or anything [] I’m sure that’s not the typical experience, but still, it was enough to make me not even bother.
 
I’m pretty sure there are flights from Barcelona to Ibiza as well… not that I’m pushing for Barca or anything haha… but like I said, if I had to pick…..

pick 2 places

i’d recommend barcelona for sure

much nicer to have 5 days

I’m in somewhat the same boat…I want to spend time in Spain, don’t know exactly where.  I’ve heard enough good things about Barcalona from lots of people, so that’s a definite.  The end of my trip is 1st-2nd week in August…and oh yes, that means San Fermin wraps up the trip (in case I get gored, ya know, I’m on my way home anyway…[8D]).  So that’s Barca and Pamplona.  A friend of mine spent 2 weeks in Malaga last summer…an exchange student from senior year lives there…and he LOVED it.  I’m hoping to chill with him for a few days too, so after that I can offer a more firsthand account, but for your trip I’ve heard great things about the Costa Del Sol!
 
Ibiza’s a little further up the coast…as I hear it it’s extremely fun, and doubly expensive haha.  For a solo traveler (like myself) I think it’d be a little too pricey.  Some clubs charge covers of over 50 euro!!  I don’t even want to think about drinks.  Sure, you can buy your own booze pre-game, but it’s kind of nice to have a drink in a club without shelling out your IRA.  I’d love to check out Ibiza one day, but I think I may need to do it 1) with a few friends, 2) with some more planning, and 3) with some money saved up just for that!

4-nights is definitely not enough for a visit to Spain’s mainland.  If you get to Madrid, you’ll need at least 3-days; add one for Toledo and another for Segovia. Sevilla will be very hot, temperature-wise in July.  Consider a route from Paris to Hendaye/Irun so your start in Spain is San Sebastian.  Head west to Bilbao, then Santander, Madrid, maybe Pamplona for los SanFermines, then Barcelona.Ibiza is totally out of the question if you’re sticking with your tight schedule.    

I would not skip Barcelona for Ibiza, unless you’re only there for the party and beach scene.

 
It was just completed last week.  AVE trains between the two cities are now in regular operation. []
 
And that’s the beauty of AVE.  Have limited time in Spain?  You can squeeze Sevilla, Madrid, and Barcelona all into 5 days.

Wicked. Yeah I could fly into either Madrid/Barcelona and then fly out of the other. I suppose I should have to book this train ahead of time so I don’t miss a flight.

Edit: Bahn says it’s not bookable via the internet.

Most things aren’t, it seems. Just book it as soon as you get to a train station once you’re there. Or if you’re really worried about it, you could try Euraide. If you want I could find the phone number for you… basically this service that will… for a fee… make all your reservations and stuff for you and send you the tickets in the mail before you leave. If you can totally nail down an itinerary for your whole trip in the next little bit here, it’s something to think about. But if you wanna leave it “open”, I wouldn’t do it as it wouldn’t be very cost effective.

I used Euraide on my last trip because I basically had a rock-solid itinerary and knew when I’d be needing reservations for the whole month, and there were several.  
 
EDIT: Just looked, the site is just http://www.euraide.com/ haha. Pretty primitive, but don’t let that put you off if you’re thinking of using them; it worked fine for me

I’m using some flights for the trip so I do have to plan it out, we’re booking most hostels as well. I don’t know how I feel about paying somebody else to book my stuff though.

And I heard that buying them directly at the train station is much cheaper?

Well yeah, if you use Euraide, you’re paying for the convenience and peace of mind; you can go to Europe knowing that you already have your reservations so you can just enjoy yourself instead of having more things to worry about. Plus, you can’t really reserve most things over the internet either, hence the third party.
 
That said, it all depends how soon after you arrive you’ll need a train reservation I guess. Regular seats, you could probably almost reserve on the day of. For bunks, you’d wanna have a couple days notice. 

The only thing I might need a bunk for is munich>amsterdam, but we’d be there about 4 days in advance. And if there was none available i’d just reserve a regular seat.

Fair enough []

hi
 
yea i would say Barcelona,Valencia.Granada,seville then if you wanted to,go on to Lagos in Portugal,nice beaches/clear water.