Wow, I can't believe nobody's even bothered to mention the style from the definitive hacker movie. Just absolutely gobsmacked. You may not like it, but this is what peak performance looks like:

Notably missing from this picture: rollerblades, fingerless gloves, neon dyed hair, tons of fishnets (which I guess you could probably stylize as fish.nets or something), puffy vest, etc.

In my day, being a hacker meant dressing like a weird raver/punk and sending people a GIF of a laughing skull, and that's how we liked it