Wireshark 
7z 
Ollybdg (1 Shadow & 2) XP 
xdgb64 (guest)
IDA (host and guest)
Windows Debugging Tools (host and guest) Offline Symbols
Mozilla Firefox
PEView 
Imprec 
Scylla
LordPe 
PEtools
Fiddler
HXD 
FileInsight
VIM
Install Watch Pro 2.5 (XP)
PowerToys for Windows XP (right click command line)
Bintext
Dumpit
gmer (guest)
pdf-parser, pdfid.py
PEID
RDG
Sysinternals Suite
Process Hacker
Rohit API Monitor 
Kerberos API monitor
010 Editor 
Python
Pefile
pydbg
FunDelete 
Resedit 
upx
Hash Calc
dnspy
Pycharm
Chrome
Visual Studio
WDK
git bash (host)
de4dot
LINQPad4Setup
Regshot 

Recommended via @m0n0sapiens, @fancy__04, @push_pnx, @tobaslouis,  @jared703, @hiddenillusion
Winappdbg  
ResourceHacker
sublimetext
malzilla 
DeDe/IDR
putty
notepad++
Dependency Walker
VC runtimes
Yara
bkdump or injdmp  
fakenet
pdfstreamdumper
malcode analyst pack
capturebat
CFF Explorer
inetsim
Yara