In Kerbal Space Program, I have launched rescue mission to save stranded Kerbals that took several hours of planning and flying. Anytime an engine breaks off a lander or a ship runs out of fuel, I feel compelled to send a robotic rescue mission to bring them back home (even though they won't die when merely stranded).

I'm not sure what about the game creates that feeling, but I think the game is much better because of it. Some of my best moments in the game were during rescue missions (one time I had a lander on the Mun with no docking ports and only enough fuel for a short sub-orbital hop; I managed to rendezvous with the lander mid-hop, then EVA the kerbal into the rescue craft.)