Open Discussion: Favorite Modeling Tools

Over the years you pick up a lot of miscellaneous tools for your modeling needs.  I've gone so far as to pick up most of the same tools you would need for home repair and improvement!  A fact not lost on my wife.  There are a ton of little tools as well that all have special and specific uses for each and every material you could be using on a certain project. 

The question today is all about your absolute favorite tools and equipment.  What tools would you say are a MUST HAVE for those just getting into the hobby?  What tool could you not go without?  Or just what are you constantly using? 

For me, when I'm thinking of modeling, I'm thinking of terrain.  Terrain building creates new challenges and makes you look for tools to speed things up and save you headaches.  One of the best purchases I've made in that regard was a hand held mouse sander.  When you're working with MDF board, there is nothing better than a power sander to bevel off those edges. 

So let's have it?  What is your absolute favorite modeling tool?  How about old tools you've found new uses for?  Comment, Reply, Discuss!