There are plenty of good code around. Study Linux Kernel if you want to get really high!! Basically, depends on where your interest lies .. find a good open source project in your area of interest and figure out how it works ...
Exactly. It depends upon which language, framework, programming style, etc. For game code you can look at ID's work. For java I hear the Jenkins code is very good. Ask around, there is no shortage of good code.
My point is that as an apprentice you should study the masters. Try and duplicate their work through practice.
Jenkins code is alright. It has a little bit symptoms of "being written by one man" (Kohsuke) to it but I wouldn't call it very good.
Here are a few projects with good Java code: Spring Framework (check mostly around the spring-core stuff), Apache DS, Google Web Toolkit APIs, Google Guava, Google Guice (pretty much almost all Google Java open source projects have similar high-quality).
