Just seen the Shadow on ebay and thought, they are generally a good bang for the buck even though I have not clicked with mine, what would recommend as the best cheap DMD games for those on a low budged looking at getting their toe in the water.
I can only comment from my own limited experience of owning/playing or from feedback and price trends.
Star Trek the Next Generation
Creature from the Black Lagoon
Getaway High Speed 2
Bride of Pinbot
All these are still fairly priced, OK some are not the best games in the world but they are still good value for money, WH20 would have been high on that list in the past but that one has crept out of the ballpark methinks.
Obviously there are way better suggestions than these, I am just throwing in some ideas.