I voted for D&D games, only.
I originally used the minis from my old Hero Quest game I got back in the early 90's, having all 4 expansions released in the US and two copies of the base game meant I had a pretty decent library of cheap, molded plastic figures. If I want to throw 20 orcs at my PC's, I've got the cannon fodder to do it!
I never used metal minis, and I never will. I don't like painting them, they're way too expensive, and they're hard as heck to carry around to games.
When Mage Knight came out, I bought many packs of that, and used a hobby knife to pop them off their little "clicky" bases and transplant them onto 1-inch squares of clear plastic with some super glue (a local hobby shop is great for that sort of thing). When MK: Dungeons came out I got some more, as those were better for D&D (less unusable steampunk junk, more classic monsters).
By the time D&D minis came out, I thought I was satisfied with what I already had. At Gen Con this year, I made it a priority to pick up common MK minis (and some HeroClix stuff, they have some have neat monk and samurai types). I found that at 3 different booths I could get MK/HC commons for .25c each, maybe .50c in a few cases. D&D minis were almost always $1 each, just for the commons! If I want an army of kobolds, I can pick them up a lot cheaper from WizKids than I can from Wizards.
But, D&D Minis did have the advantage of monsters that only D&D had, or were most common by far in D&D. So I found one guy who had some D&D commons he was willing to sell for $.50 and picked up a few, and since then I've bought a few packs of D&D minis at my FLGS. I normally just remove them from their little black bases with that same knife and superglue them to a bit of clear plastic (so you can see the terrain beneath them, it helps with the visual aspect of the game IMHO). I don't do this to rares, unless it's a rare I really, really want, otherwise I can resell them to partially recover the costs of buying minis.
The only problem is, I hate a lot of the 3e art that they based their miniatures on: anorexic displacer beasts, "iconic" characters, hell hounds that look like wolves with mohawks, and Gorilla-style Orcs.
When I saw that the one mini I actualy wanted, a Mind Flayer, had a resale value on eBay of around ~$25 I was stunned and saddened. If I really, really wanted one for my game it would be far cheaper to buy a metal mini and paint it. ~$25 for a piece of poorly painted injection-molded plastic that cost maybe $.10 to make?
What I wonder is: Why hasn't anyone just made big bags of cheap, injection molded unpainted generic monsters? Like those Army Men or Cowboys & Indians bags they have at toy stores, make a big bag of Orcs, or Men-At-Arms, or Undead, or the like, they'd probably sell great to the "discount mini" crowd, and they could even get non-gaming sales to little kids
