I was using Texmaker as my LaTeX editor on Windows until recently. It was sufficient as an editor, but I was not fully happy with its autocompletion and multi-file UI. I came across TeXstudio, which is a fork of Texmaker and it turns out it fills out all the features I felt were missing in Texmaker and it seems to be more updated. For example, the autocompletion of LaTeX commands, references and citations actually works. Also, if you have structured your document as multiple LaTeX files, compiling from any of them compiles the document. If you are a Texmaker user, do try out TeXstudio.
Tried with: TeXstudio 2.3 and Windows 7 64-bit