We used to use candy - smarties, M&Ms, etc. When you'd kill someone, you get to eat them.
Of course, we ended up having players ignore the "big bad" in a combat to clean up all his henchmen (yum!), and then we'd get a TPK.
We've been putting out counters since our first product, NeMoren's Vault, which is now 4 years old! In August 2001, we released Counter Collection I: The Usual Suspects through Sword & Sorcery. This contained an assortment of 3.0-sized counters of the regulars: orcs, goblins, undead, etc.
A second set came out with more characters, monsters, and stuff like that.
We also released a bunch of "Counter Packs" that were built around a theme: Demons & Devils (which tied in to the excellent Green Ronin books), Dungeon Dwellers (which featured the counters needed for Rappan Athuk!) and others like that!
When 3.5 came out, we began releasing our larger collections in metal case packaging, which provided much needed storage and transport capabilities.
The first, which came out in March, was a Summoned Creature collection, featuring the creatures that would be called through a summon creature or summon nature's ally spell.
After that, we put out Counter Collection Gold, which, along with the Summoned Creatures, covered just about every monster in the SRD. This was a limited edition product, and has since sold out at the distribution level, but there are still lots of copies floating around in retail locations.
TODAY, you should be able to find Counter Collection: Undead at your favorite retailer. It features all of the undead from the Monster Manual -- uh, I mean the SRD -- and lots and lots of other undead from other sources, mostly the brain of Claudio Pozas.
All of the counters are printed in full color on durable cardstock. They are sized for the d20 rules, and feature the art of Claudio Pozas, some of which you can see hosted by this very site.
If you're more of a Do It Yourself kinda guy, we also have Counter Collection DIGITAL available at retailers everywhere (and through the online White Wolf store) with 1200 jpeg images that you can manipulate and print out with your own software (I use Photoshop, some people just use Word).
We've also released several of these products as e-Books through DTRPG.
Hope that helps!
- James