XYplorer Beta Club

+1 for Beyond Compare as a file/folder compare tool that can do simple sync jobs as well. I use it for merging changes in source code mostly, and sometimes to sync the files I have backed up on my USB drive.

I've also used the free SyncToy from MS to keep folders with images in sync on multiple machines.

cwRsync

Thanks everyone, will try them soon.

Tried them all, thanks again. But found one more nice one FreeFileSync.

My favorites in that order are: FreeFileSync, SyncBack and Create Synchronicity. They all have very good features, i ordered them according to ease of usability.

i should mention that XY's sync select was incredibly useful in viewing what's missing from both panes etc. I would say with some decent scripting with backup command XY is almost very close to those mentioned above.

Free HMMMM , not free but one of best fastes and no mistake even if u change a dot in txt file is Good Syncronizer

"I tried them all". I use for years ViceVersa Pro. It is excellent, complete and reliable. http://www.tgrmn.com/
I have a complaint, however, the performance is not so good, especially with small files. But overall I have not found better so far.

On Mac, nothing beats ChronoSync
http://www.econtechnologies.com
and in this case, the performances are awesome.