A cheat-sheet for reverse engineering malware, by Lenny Zeltser.
A disassembler for Windows. One of the best in the field, and v2.0 just went beta. It's shareware, though it doesn't appear to lack any functionality if you haven't purchased it yet.
A toolset for taking apart Android .apk files so that the binaries can be reverse engineered or modified.
4983 links, including 378 private