A mid-season replacement TV series is a show that takes the place of another cancelled show due to poor ratings or some other reason between December and May. These shows are often second stringers that didn't make the fall line-up. Networks are hopeful they will catch on, but often their role is to hold on until the roll-out of the new fall line-up. Every once in a while, networks catch lightning in a bottle and these fill-ins become wildly successful, anchoring the network's lineup for years and spawning multiple spin-offs. Which mid-season replacement comedy TV series* best filled its role as a fill-in and more? * minimum four plus seasons with December through May premiere Vote in the companion poll: Mid-Season Replacement Drama TV Series Discuss the topic here.