Model 1 Arcade Board
The next big thing will be a decent working Model One and a Two arcade boards produced by Sega. Virtua Racing, Virtua Fighter and Virtua Cop and sequels. All great games!
Although I still regard MAME as the King of emulators. Computer and console emulators are good but you can't play arcade perfect games on those! Compare Bombjack and any of the computer versions - you just can't compare! MAME will just get better and better and will probably include 3D games in a few years too!
If you havn't guessed it already, arcade emulation is my favourite!