A very important thing in order to perform on top as a software developer is to have good equipment. I see many companies pay good money for decent cpu's, enough of RAM and dual monitor setups - and as an aspiring software craftsman I truly value quality over quantity. So far in my career I've only been at companies with great chairs and really good electrically adjustable desks. However, what many forget is to buy truly great monitors (dual is a separate wish) and keyboards.
To have many screens isn't worth much if you cannot view them without being directly in front of the screen. In other words, I think viewing angles are the most important aspect of a monitor. Other important aspects to consider are size, resolution and video connection options.
The most undervalued asset used when developing software is by far the keyboard. In 2007 I bought my first mechanical keyboard. I used it everyday for more than 7 years and it still works flawlessly. Now it has been replaced, not because of failing condition, but because I've found mechanical switches that I like even more. I have a small mechanical keyboard that I bring along when travelling. I would even go as far as to say that a mechanical keyboard will make work more fun. Boring tasks will become less boring.
As a side note. I don't happen to only like software - I like hardware too and I have been building computers since my early teens. In early 2007 I bought a high end CPU cooler - Noctua NH-U12F. It was expensive, but it has followed my system through 4 motherboards and 5 cpu's. The product itself is discontinued but Noctua still supports their customers by sending out mounting kits to support even the latest cpu's. As a matter of fact, it just followed along to my brand new i5-6000 build and it performs great. That is what quality is. It means that not only software quality is important to a software craftsman, but hardware too.
If you too care about quality, maybe you will find it interesting to attend Agile testing day Scandia in Gothenburg where I will have a workshop on TDD, which is a technique to craft high quality code. Now and for a couple of days, you can get 40% off by using their super early bird coupon. Read more here: http://www.agilescandia.com/