Is aspergers really a illness? Because to me it seems like someone that doesn't want to be like the majority of society and for that they slap a medical sticker on it.
No, it is not an illness per say.
Modern psychology has sort of degenerated into a system of labels for normative deviance, often with the intention of providing pills to "fix" the disease. I view the over eager labeling trend as the middle variance trying to claim a correctness, some kind of superiority based on numbers. Numbers do not make wisdom, in fact studies suggest they make the opposite. It has great academic usefulness in terms of allowing study of specific behaviours, but it is too often used to define an individual as a problem rather than question the context surrounding that person. As I see it, it isn't a disease it is just a difference in style with negative social consequences but strengths in other areas.
Are there differences between someone with Asperger's and someone who is "normal" ? most certainly but normal is of abstract reference to the mean, simply where people tend to cluster, there is nothing inherently correct about being closer to the mean. IQ tests for example represent people based on their deviance from the mean, deviance in one direction being good and the other being bad, but again it is a highly subjective criteria. Sometimes the same deviance is good or bad depending on the context you use to measure it. Much of what makes someone socially powerful in our current society can be functionally useless or counter productive outside of that context, and in a different society could be viewed as highly deviant and ineffective.
Homogeneity (clustering around the average) is as often a bad thing as a good thing. It can result in stagnation and collapse, change originates from outliers. This may be part of why mentally deviant people are often incredibly creative, in a sense they think on the edges where others stand somewhere on the hill so they have a different view of the world.
Labels like Aspergers, ADHD, and similar diagnoses have an enormous amount of overlap and it is incredibly difficult to accurately label anyone with a psychological disorder due the complexities of the variables involved. More so even because the disease itself is an entirely arbitrary creation. Only in extreme cases does anyone seem to perfectly fit a diagnosis and even then it is prone to error and misinterpretation. Fortunately there is a growing body of psychology professionals who are trying to move away from the pharmacological reliance of current medicine, and back onto understanding what causes deviance and how to actively deal with the upsides and downsides of it.