My favorite is Germany.
Spain probably still has the best team, but the players have won nearly everything in the past few years (European Championship, World Cup, Champion's League). The players won't be 'hungry' enough; furthermore it seems nearly impossible to defend a title successfully. As far as I know, Brazil was the last country who won two world cups in a row ('58 and '62), no European Champion ever defended the title successfully and no European team ever won three titles in a row (World + European Championships)
The German players haven't won anything yet, so are very, very hungry.
Spain also misses Villa upfront, an enormous loss. Torres never reached his very best level after his injuries, so they won't have any world class player upfront.
Holland is not at its best
Some important players just got back from serious injuries and lack rhythm (Afellay, Sneijder), others (Van Bommel, Kuyt, Matthyssen) are over their peak. And we simply don't have a good defense.
France and Russia are my dark horses, but I don't think they're serious contenders for the title.