THe Ultimate Reversing Tools Library - http://www.woodmann.com/collaborative/tools/index.php/Category:RCE_Tools
(start by clicking on the menu ont he left)

Here are some quick grabs:
Static Analysis
IDA Free Download (on the class vms) - http://www.hex-rays.com/idapro/idadownfree.html
Hexplorer (runs in wine) - http://sourceforge.net/projects/hexplorer/

(gdb/objdump/nm/nasm+ndisasm of course)

Dynamic Analysis

Ollydbg (windows) - http://www.ollydbg.de/
PaiMei (windows hit tracer) - http://code.google.com/p/paimei/
Radare - http://radare.nopcode.org/new/
Eresi (nix centric) - http://www.eresi-project.org/
Diff Conv - http://www.semantiscope.com/tools/DiffCov-20090930.zip //  
TodoHT (ptrace utils) - http://rpisec.net/projects/show/todoht
BioGB HT (gameboy) - http://rpisec.net/repositories/show/biogb-ht // http://www$

Misc

Java Decompiler - http://java.decompiler.free.fr/
.NET Reflector - http://www.red-gate.com/products/reflector/