I have two 3D dungeon maps that I've designed and built from scratch. One is grey with hexes and one is brown with squares.
I don't use them all the time, but I do use my battlemat which I also made myself (like this).
I have lead/pewter minis that I have painted. I have minis I've made out of Sculpey. I have LOADS of MageKnight minis that I bought off eBay and I have a lot of D&D prepaints that I purchased from Mini Market.
As great as all of that is, I love finding "minis" at the dollar store, Big Lots or party store. I'm old school and if it's about the right size; prepare to meet it in battle!
Here are some of my latest acquisitions. I think they are great and I'm looking forward to throwing them at my players! Prepare for TPK!
These guys are called "Biloko" and are from the Secret Saturdays Cartoon. They are awesome giant apes or mutant baboons or somesuch. I see them as guardians of some forgotten temple...
Some sort of basilisk or iguana also from Secret Saturdays
A "Rakshasa" from Secret Saturdays. I'll probably use it like a sphinx...
All the Secret Saturdays minis were $1.50 each at Big Lots.
Nine frogs for $0.99!
Temple of the Frog anyone? These were $0.25 each at the party store
One quarter -- venom included. Save vs. death please...
$0.99 at the party store on sale
$0.99 at the dollar store. Gulp!
All of this death and mayhem for $17.25 plus tax. You can't beat that!