C# Complete	Best of 7 C# books in one. I reach for this before looking to Google or MSDN.
	jQuery in Action	Fantastic cross-browser Javascript library. I use it often.
	JavaScript Pocket Reference (2nd Edition)	Because we all need a hint now and then.
	The Essential Guide to Open Source Flash Development	Why spend hundreds on developing Flash? This book + FlashDevelop = inexpensive education on high-price skills.
	Lucene in Action (In Action series)	Very powerful embeddable indexing engine. I use it as part of Solr.
	PostgreSQL (2nd Edition)	This has been a huge boon to my database management skills.
	ASP in a Nutshell, 2nd Edition	Great object reference for those still using legacy ASP. I still have mine.
	PHP and MySQL Web Development (4th Edition)	I bought two good references at once when I picked this up.