Well last season has to have been one of the most exciting in recent memory, with Real Madrid recapturing the title after a three year absence. Most expected Barca to reign on all fronts, but despite having probably the most talented squad in Europe, they failed on all fronts (including getting knocked out of the CL by some small club from England).

As if they actually needed any more attacking talent, Barca have really thrown down the gauntlet by bringing in Thierry Henry to add to what was already the most frightening attacking trio in the world in Eto'o, Messi and Ronaldihno. With all the aforementioned likely to stay now, it will really be interesting to see how they are all used, and infact, whether all four of them can fit into the same side on occasions. Elsewhere at Barca, they have brought in Yaya Toure, Eric Abidal and Gabriel Milito and seem set to let Deco, Edmilson and Gudjohnsen go. Guily has already gone to Roma. Whatever anyone says, they really look the team to beat this season.
Real Madrid will have their work cut out to retain their title, especially considering they just sacked the manager who just won their first title since 2003. Obviously Beckham (one of their best players last season) has now left, Helguera has gone to Valencia and the mercurial Roberto Carlos has moved on to Fenerbache after ten years at the Bernebau. Only De Stefano played more games for the Spanish Club. On the plus side however, they have brought in Javier Saviola (ex Barcelona

Valencia have brought in Helguera to replace Ayala, who has moved to Zaragoza. More importantly for them though, they have managed to hold on to their main man David Villa, despite interest from a host of top European clubs. They have a nice mix of youth and experience so it will be interesting to see how the younger players do. Obviously David Silva is probably the most high profile of these youngsters but the likes of Arizmendi and Alexis will be exciting to watch.
Sevilla have been the surprise success story of recent seasons after two UEFA Cup successes but their main problem is trying to hold onto their best players. Daniel Alves has been linked with every team under the sun (Real Madrid, Chelsea and Liverpool) and the situation is still unresolved, especially since Sevilla have just signed Boulahrouz on loan from Chelsea as a possible replacement (why?)

In terms of possible outsiders this season, I don't think you can look any further than Athletico Madrid, Villarreal and maybe even Real Zaragoza.
Athletico Madrid are the Tottenham Hotspur of England in that they have so much promise every season with players coming in from everywhere but they generally fail to deliver. This summer they have lost their main talisman and Captain, Fernando Torres to Liverpool and have replaced him with Diego Forlan from Villarreal. The golden boot winner two seasons ago, a lot of Athletico's success will depend on Forlans success. They have also lost Galletti but have seen Luis Garcia arrive (as part of the Torres deal) along with Simao Sabrosa from Benfica. There are strong rumours of Riquelme also joining so if that's the case, surely CL qualification should be on the horizon?
Villereal have lost Forlan and brought in Jon Dahl Tomasson to play alongside the extremely talented Nihat. Robert Pires is also fit after missing a large proportion of last season through injury. At Zaragoza, they have replaced the outgoing Milito with Ayala (who hasn't even played a single minute for Villarreal) and have also brought Francisco Pavon from Real Madrid as a replacement for Gerard Pique, who has returned to Man United after his loan spell.
Just quickly, a special mention to Chris Coleman (a very good manager by the way Sabre)

As for this season though, I can't look past Barcelona. They just look so strong in all departments. There can certainly be no excuses for them this year anyway.