Sincerely, I do not see much difference between the guys that are considered bad boys or nice guys. To me looks all normal and I will say that all of them are overall good guys. What I have notice that all the guys defined as bad boys are very good looking.
In my opinion, almost all the bad boys are just (nice/bad) guys with good looks and nice guys are just (nice/bad) guys with average or less than average looks for the particular girl (what is consider attractive depends on the girl).
Most Helpful Girl
It's all in their confidence, not their looks. That's why you can't see it.1
Most Helpful Guy
A guy can be good looking and be a 'nice guy' or he can be a 'bad boy'. A good looking 'nice guy' will might be called "cute" by girls whereas a good looking 'bad boy' might be called 'hot'.
A bad boy is often confident.. to the point of being cheekily arrogant, he's assertive, doesn't take life too seriously and isn't afraid to put himself out there. He's not going to run after a girl and is often seen as more desirable for that reason.. But can sometimes show too little care and be considered a jerk by some girls.
A genuine nice guy will give a girl a lot of attention, will often view her as being above him and can sometimes appear somewhat desperate. Usually nice guys are more of the 'beta' type.. But can still be good looking. It's just a personality thing.