Texts and projects to familiarize myself with compilers?

I'm currently a college senior (majoring in CS) who intends to enter grad school after completing my undergraduate degree. I've become very interested in the topic of compilers and am considering writing my master's thesis on some compiler-related topic. What texts and projects can you recommend to gain a deeper understanding of compilers and potentially interesting avenues for research? So far, I have read the Aho and Ullman dragon book, but not much else.