What is the best cell phone company in Spain?

There are three big ones Vodafone, Amena, and Moviestar,

What is the best deal when it comes to prepaid calling, with a sim card. I also want to be able to call one number cheaper then normal rates.

You have three companies:

Movistar, Vodafone & Amena.

Movistar and Vodafone are more less the same prices; movistar have more connectivity and Vodafone have more promotions.
Amena is bullshit

I'd say Movistar. It is the same network as the British company 'Orange'. Hope this helps!

i don't know i never been to Spain.

I really don't know in spain but in the USA the best to me is not sprint so I would say Alltel.

I lived in Madrid and was with Movistar, their rates were comparable and their coverage excellent. Don't think you'll do much better than Movistar.

Amena are crap, they have no coverage. Movistar have good coverage but are always trying to sell you something, also Telefonica have a monopoly here in Spain and more or less charge what they like and answer your problems when they like. Apart from that they're not bad. I have a sim card with Vodafone and they have great reception and all in all I have nothing to complain about - apart from maybe a new job perhaps!

Vodaphone now trades under its own name in Spain and gives very good coverage.

I am with Movistar but its not the cheapest. I believe I may be paying around 15 cents for a text message to another Movistar phone but if I want to text outside Spain it costs 50cents to send the message and another 40cents to get one back!

I understand from my friends that Vodafone has the best deals as if you are Pay as you go you can register on the internet for a points system so that you get points for using your phone and then they give you discounts or free texts in return. Its not much but at least you will get something back for your money.
Hope this helps.

Nobody. Everyone intends to get your money without a good service return.

There are 3 mayor companies in Spain for cell phones. Vodafone, Movistar, and Amena. I would personally pick out from the 2 first ones, they have a complete coverage for all the country. Amena is almost getting them now and has very good prices if you want only a top up phone and not a contract. Also if you are going to the North you can find companies like Euskaltel, that can give you a very good offer, but, always under contract.