In no particular order

====== RE tools ======

**IDA - oblig **
https://www.hex-rays.com/products/ida/index.shtml

**HEX workshop**
http://www.hexworkshop.com/


**PE - Bear **
http://hshrzd.wordpress.com/pe-bear/

**C4 Decompiler **
http://www.c4decompiler.com/downloads/

**GUNpacker**
http://www.woodmann.com/collaborative/tools/index.php/GUnPacker


**API Monitor**
http://www.rohitab.com/apimonitor

**XN resource Editor**
http://portableapps.com/apps/utilities/xn_resource_editor_portable