Lately i'm working with:

- Photoshop
- Pen and Paper
- Cinema 4D 9 (non-commercial use)
- ATIs The Compressonator
- MED, SED, WED
- MS Word
- Camtasia Single License


i guess that was all.

+ google.com image search, turboSquid texture and art resource

Edit: i realized i was slightly off-topic and a little incorrect.

so, my musthave's:
blender
+
paint shop pro 5
+
gs

but blender's my biggest one. if i didn't have gs, i'd find something else (probably irrlicht, coz atm i wouldn't want to spend money on something besides gs), but blender is fantastic for heaps of things. it destroys windows movie maker when it comes to home-movie editing, and so i'm using it with a few of my mates to make a fight movie during my free periods at school. and of course, it's a fantastic modeling tool.

julz

All of these lists don't have PC/Mac listed in them

All you need is computer + paper + pen

For sound/sample creation, editing, recording, mastering, effects and atmo:
NI-Reaktor
http://www.nativeinstruments.de/index.php?reaktor_us&ftu=397ca2c98c3459d&flash=9
It´s the best and powerful software synth/sampler/effect if you ask me. You are able to construct any possible and impossible sound machines.

For bones animation and seamless export to mdl7:
Fragmotion
http://www.fragmosoft.com/

i use 3DGS with:

Microsoft Picture it- skinning, bitmap creation,a fantastic all in one tool for graphics.
milkshape/fragmotion/MED- for modelling(low poly with a great skinning tool is awesome if you know what to do).
Cool Edit Pro 2.1- for in-game music production, sound effect editing, various other options for audio.
Pencil and Pad for concept drawing, character design.