With a plethora of minis manufacturers, both current and in the past, a D&D gamer would presumably be well served with minis to use in the game. Unfortunately, with the plastic collectable minis game still in-market, there is no official unpainted metal minis for the D&D game.
While over the years several companies have held the license (Minifigs first, then Grenadier, then Citadel, then TSR directly, then Ral Partha, and finally WotC directly) and a lot of minis have been made in that time, some are hopelessly obsolete (Minifigs), very hard to find (Citadel), or out of scale (Grenadier, first TSR line, and Ral partha) with the current ranges of figures on the market. And while the DDM collectible pre-painted miniatures are good for either casual gamers (or those that do not want to paint), they lack detail, the paint is sometimes overly thick, and cannot be stripped easily.
Otherworld miniatures burst on the scene a few years ago. Using a loophole in the OGL contract from D&D 3e era, they have been producing miniatures using the old artwork from first edition AD&D. I have a few, and in general really like them. Not only are they very well sculpted, but are dead ringers for the old AD&D artwork.
Recently, I was excited to see new releases of the venerable Hook Horror and the Owlbear (set to release on 30 September 2009). Both of these minis are very welcome; there has not been a Hook Horror on the market for decades, and the closest substitute from 3d party manufacturers is less than stellar, while the Owlbear is always welcome (again, with all 3rd party substitutes being sub-standard). While I already have the old Chainmail metal Owlbear (which is fantastic), a current and in-production version is very welcome!