I would rate Suarez higher than van Persie to be honest, and even though Ronaldo didn't show much this tournament he would still certainly deserve a spot in the top 5 based on his performance the rest of the year. Remember that he has been playing while less than fit during the Portugal games.
Although Robben technically is not a striker, in his current form is up there with the greats. What a beast. Excuse me while I do include him in my best 5.
Based on today's performance, actually, I give Suarez the top spot. My list would be:
1) Suarez
2) Ronaldo
3) Robben
4) Messi
5) van Persie*
* To be honest, based on chauvinism and his showing this tournament. If based on the rest of this year, he'd come nowhere near the top 5. I would probably place one of the German chaps here if I were more impartial, but being Dutch I can't bring myself to do that.