I can think of one major franchise (Star Trek) that could do with ten or so years off. Honestly, what the BBC did with Doctor Who (even the TV movie in the 90's to test the water) has been brilliant. They took a show that was milked dry off of the air and WAITED INTELLIGENTLY until they saw they could relaunch the series with an interest. Even better, it is still in the continuity of the old series, so that all of that didn't basically mean nothing to a new audience, and it spurs interest in the older series as well, which could benefit DVD sales.
I think a lot of franchises could do this, especially Star Trek. Hell, even ER, which still gets decent ratings but has definitely jumped the shark, could do this and return a few years later. This is what I hope happens to Stargate eventually as well.