As a profession I'm a Software Engineer, but I also enjoy being an all-round nerd in general. More here later.
Stack Overflow
Q&A for professional and enthusiast programmers
Super User
Q&A for computer enthusiasts and power users
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Information Security
Q&A for information security professionals
Server Fault
Q&A for system and network administrators
Raspberry Pi
Q&A for users and developers of hardware and software for Raspberry Pi
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
Android Enthusiasts
Q&A for enthusiasts and power users of the Android operating system
Computer Science
Q&A for students, researchers and practitioners of computer science
Reverse Engineering
Q&A for researchers and developers who explore the principles of a system through analysis of its structure, function, and operation
Network Engineering
Q&A for network engineers
Ask Different
Q&A for power users of Apple hardware and software