Jane's 688I.
Whether this genre is for you will depend on what you want out of a sim. The SH series will provide a prettier and more emersive environment, and better campaigns, than 688I/SC/DW. But the modern subsims invovle better technical models of the sensors, weapons, and environment, as well as an intense head to head MP setup. Also, DW et. al. go more into the specific systems of the platforms, allowing (requiring, if you care about results) you to get your hands dirty, while the SH series is more about command. IMO, DW et. al are better simulations, but aren't as good as making you forget it's just a simulation.
