Like I said, on a match by match basis, i.e. unpredictable results. You still get more 'shock' results here than the other previously mentioned leagues. The top 6 here is certainly a lot tighter in the Premier by the end of the season rather than say Real or Barca being 70 odd goals in front!
Probably better to say which league is less predictable on a match by match basis and the answer is the Premier League. French, German and Spanish leagues aren't so much. IMHO that's why the Premier League is the best to watch.