Sauske has Sharingan, its a bloodline trait and he activated while fighting Haku. Sauske learns Chidouri from Kakashi, nothing to hate upon, he learned it, he was even able to manipulated and make Chidouri run through his body, give him props for that. He received the curse mark by Oro and was able to power up because of that, yea he had to learn how to control it and such but he was only able to obtain certain powers because the curse mark was given to him. Then later Itachi takes it away but gives him MS, true Sauske had the chance to get it on his own but didnt, no matter how much people argue this point, Sauske didnt get it when he had the chance. Meaning he wasnt mentally strong to kill Naruto and gain it, he also states he didnt want to obtain power like Itachi did, meaning by killing his best friend. So all and all said, Sauske was given MS. Only reason why he had summons was because he had Oro's powers, he beat Oro but when Oro was already weaken and in bed. Sauske did not beat Oro at his max. He gained Oro's powers and was able to use them, so another thing he earned by fighing someone who was sick. Now he has his own summon of the Hawk, ill give him that, im sure he learned that on his own. Now he has EMS which once again was given to him, even though there's no other way of getting EMS besides transplanting their brother's eyes. Yea that's the only way an Uchia can obtain a higher degree of Sharingan is by killing their best friends and transplanting eyes.
So let's recap:
1) Sasuke learned Chidori, some fire-style stuff, and decent taijutsu on his own. He learned these things several years ago as a child and a student.
2) His sharingan was basically given to him through genetics. Plus, Uchiha were generally considered very good fighters, and Sasuke inherited that talent.
3) His cursed seal was given to him, against his initial wishes, by Orochimaru
4) His MS was given to him by Itachi
5) His EMS was given to him by Madara
6) His hawk summon doesn't require "work", it only requires that he sign a contract (which somebody probably gave to him).
7) He did kill Orochimaru and absorb some of his powers, but did it when Orochimaru was sick and in bed.
Sasuke has two things going for him: He's extremely angry (and his anger fuels his chakra), and people keep giving him power.
Now to Naruto. Ive read plenty of people argue that Naruto has the 9 tail fox and he was given that power, true, but HELLO PEOPLE this is the point of the whole Naruto manga, the tail beasts. Someone had to get it, Naruto is the main character, this is how the story goes. Naruto learns the rasengan from Jman. Naruto works on his own and creates the Raseshiruken after just a lilttle help from Kakashi and yamato, he created something that even the Hokage could not do. Naruto learns Sage mode, he trained for it, he learned it, it wasnt handed down to him. Thats pretty much all naruto has, Multi Shadow CLones he learned on his own when he was young and took the book holding the forbidden jutsus.
...and Naruto:
1) Naruto was given the fox. The fox does increase his power, but didn't make him a better ninja. In fact, Naruto was considered stupid and underachieving for many of the early chapters
2) Naruto learned the multi-shadow clone jutsu on his own (although, honestly, he can only create so many clones because of his high chakra)
3) Orochimaru sealed the fox again with the 5-point seal, taking away much of his chakra control
4) When Jiraiya took the 5-point seal off, Naruto gained the ability to lose more fox chakra, though loses mental control when he does.
5) Naruto trained hard to learn Rasengan
6) Naruto trained hard to learn wind-release and Rasenshuruken.
7) Naruto trained hard to learn--and master--Sage mode.
Naruto was given the fox, so he hasn't earned everything he has. However, When you compare the list of achievements, Naruto has earned more things through hard work, and has faced more setbacks in his training than Sasuke has. Sasuke hasn't had to work hard to earn power since he was a student with Kakashi; everything is given to him easily. Naruto has had several places where he has lost ground, and most of what he has was earned through lots of hard work.
In the end when the going gets tough, Sasuke isn't going to be able to win because he isn't used to the hard work, while Naruto is.