I always try to rescue my Kerbals in the best way I can. Especially the ones I have gotten really attached to. Jebediah, Bill, and Bob are always on a high state of priority when they're in their space station above Kerbin. Meanwhile my second favorite team of Kerbals would have to be Gilwise, Burvey, and Edby Kerman. I actually sent Burvey on a space mission around the Mun to survey it from a high orbit, but then his fuel cut out while I was trying to smooth it out. But during that time I was also building a space station around the Mun, so I sent another mission to go save him and then dock with the station. It was a Mk1 capsule with a 1-man lander can right above the engine. The mission was a success. Had to EVA Burvey for a long while though, he had less than 10% of his fuel left when he finally grabbed onto the lander can.