This may seem obvious, but the most important person to impress at work is your line manager (your boss). S/he is the one who has the biggest influence on what work you do, what (if any) bonus you're entitled to, whether you're deserving of a pay rise, what training the organisation will finance for you and so on. Your line manager is also the gate-keeper to more senior members of the organisation and likely a person with numerous contacts within the organisation and/or across the industry.
The only way to impress your boss is to clearly understand what s/he expects from you, then deliver work that exceeds those expectations. This applies to more than just the output itself ( e.g. exceeding your sales target), but also the way you deliver the output (e.g. the relationships you build with your coworkers, the processes you put in place etc.).
Continually exceeding expectations will result in three things:
1) you will build a fantastic reputation (personal brand),
2) you will be given the opportunity to work on those things that you want to work on and
3) you will be given chances for rapid promotion.
Please be aware, the only way that you will be given work that you want to work on, is if you ask for it. A great line manager may know what you want to do, but don't expect them to - they're likely to be very busy, with many demands on their time and thoughts. My recommendation is to exceed your boss' expectations, then ask (politely) for what you want.
A final word of caution...each time you exceed your line manager's expectations, those expectations will rise. How to handle this challenge may well be the topic of a future blog post...please let me know if that would interest you.