I'm a big fan of John Scalzi's sense of humor, especially in Old Man's War. However, when I heard about Redshirts, I was less than 100% excited. While it is ridiculous that Red-shirts dropped dead all the time on away team missions, I didn't think that the joke itself could sustain an entire novel. As a result, I waited until I could check it out from the library before reading.
Unfortunately, I was right. The central premise is funny. You've got a crew that's scared to go on away missions, and you've got characters that get shot and wounded only to recover all the time on missions. You've got technical gobbledy gook with ridiculous technical solutions, how despite how advanced the ship is, nobody sends e-mail and messages are always delivered in person. It's pretty funny, but it lasted about half the book and then the rest of the novel becomes a farce, barely worth reading.
I eventually limped along to the end, but only out of a sense of masochism. I wouldn't recommend anybody put themselves through the entire novel. Read until the sense of fun is over and then abort the mission.