One of the things I demand from any game is that is draws you in & immerses you in the experience it's trying to create.
Silent Hunter 3 does that massively.
The premiss is simple; take your U-Boat out, reach a pre-determined sector by what ever course you want, patrol it & try to sink any enemy ships you find. Simple, easy to remember.
That is, until you get dud torpedoes that cheat you out of that BIG score, a swarm of aircraft just won't leave you alone by swooping down time & again, your crew are all exhausted, an escorting destroyer is determined to depth-charge you back to the stone age, sweeping over you again & again while you desperately try to contain any damage & sneak away to safety...
The game allows you to fast-forward the cruising bit, you don't strictly have to return to base once you complete your objectives, you can program each torpedoe manually or let the game manage it, manage & train up your crew, upgrade you sub, go whatever route you want, sink what you want, Silent Hunter 3 really is what ever you want it to be.
If all you want is to drool over high resolution textures & realistic faces, go somewhere else, but if you want a fairly unique, utterly immersive & tense gameplay experience, Silent Hunter 3 really is a great game. Highly recommended.