Yes he was awesome, and therefore he should be named but, he is not that great a striker and far from the best. I'll bet on that he is nothing else then a one season wonder. And he still has to do well in European competition before you can put him in the second place. And you also have to keep in mind that La Liga is the easiest league (of the best) to score in.
I would say that none of them is the best, of that simple reason that every one of them has some strengths and weaknesses. For example Nistelrooy and Maakay is better finisher then the rest, but Sheva, Adriano, Ronaldo and Henry is better in everything else you could say that they are more complete players, so without a doubt they are the best players because they are more complete as a footballer, but they might not be the best strikers since a strikers job is to score goals and nothing else. So it all come up to what you rate highest the amount of goals a player score or his abilities. In my opinion you have to consider both aspects, so it excludes Nistelrooy and Maakay since they are not very complete. Adriano can be excluded as well he simply scores to few goals. Then we have Sheva, Ronado and Henry left and I can’t really say which one of them who is the best.
players like Gillardino a very good finisher but has the same problem as Makaay and Nistelrooy. Robinh and Tervez should not be forgotten but they are still not in the same level as those above.
Someone would might name Ibrahimovic, Crespo, Eto, Drogba, Tresequet, Inzaghi, Totti and Cassano and of cause none of them should be forgotten but none of them can be considered as the best.