Sasuke is established as best looking by the mangaka. No one else matters.
Since when?
Since when?
Since he said he wanted Sasuke to look "cool", gave him fangirls, and then said he enjoyed drawing him the most.
If you're referring to the latter part about "No one else matters"- I meant in terms of there being no factual answer to this question. Many people don't find Sasuke to be aesthetically appealing, just as many do. It's all based on opinion, but I've just personally always thought that when a creator says something about his work, that it holds more weight than a random fan's.
In whole manga the best looking character is Itachi without a doubt.