Thank for all of you providing so many exciting tools. However, several months passed, I'll share my experience and my simple conclusion.
I found that there is no PERFECT tool so far which can deal all kinds of reference formats(latex/word) on all OS (win/linux/mac) platforms. And some tools are ugly and some are expensive.
My case is sometimes I work on win/ms word, sometimes I work on Mac/linux/latex or win/latex.
Thus, I decide: Use Endnotes for windows/Word case (Endnote is not bad and it can import/export rich formats and work perfectly with MS word. In win/word case, it is BEST);
Also, I use Jabref for latex case on win/mac platforms. Jabref supports all OS platforms. Besides the basic reference management functions, it can find duplicate items and even can display "correct" author names! For example. JabRef can display "Tom and Jack" or "John et al." in the database! This feature is killing feature if you are confusing so many different confusing middle/first/last names from authors from different countries! Jabref is also supporting you fix some bib items manually because, as you know, some bibtex item downloaded from ACM/IEEE are not perfect and contain messy strings.
so far, my solution works perfect for me.
The Mendeley and other fashion tools are beautiful than Jabref. However, they are "common" reference tools and their features are not killing features for me. "Displaying authors names intelligently" kick a lot of tools out.
Also, the "cloud storage" feature is also not very useful for me. If you really need, dropbox, icloud and other tools have solved this problem perfectly. I hate to register another account for this one.
Refworks is also popular. But I think it is not useful for me. As I mentioned, the "cloud storage" is not very urgent for me. And it supports hundreds of bibliography formats, what the hell is that feature? any modern researcher needs to copy the those reference with formats manually ? I think the most cases is that writing academic paper is more "design" or "programming" rather than "writing" or "editing". The use-case is that we use tools to make the bibliography issue as automatic as possible.
So far, endnotes/jabref+word/latex+win/mac/linux make my academic writing more like programming, I just focus on the research itself and never spend time on the labor working.
What's more, a lot of ref manager tools claim that they are good at managing or searching PDF files and abstracts.... I think in the "Google" era, the folder and some built-in searching functions is not needed anymore. I just throw all PDF files into a folder without any "management"(but I name them with good file names using titles), thus, either I can find the paper PDF quickly just based on my fresh brain memory or just Google it for those old papers.