Life on Mars (BBC America) sort of fits your premise, but not entirely. A detective in 2006 is trying to solve a murder/dissappearence case, gets hit by a car (Bowie's "Life on Mars" is the song playing on his car radio when he get's hit) and he wakes up in 1973. Now he's a detective in 1973, trying to use 2006 techniques to solve crimes, all the while trying to figure out whether he's really back in 1973, or in a coma. He can hear his 2006 mother and 2006 doctors talking through his TV, etc, discussing whether they should pull the plug on him.
Very, very cool show, which is apparently getting developed by David Kelly for a US adaptation, meaning the US version will suck a$$ compared to the Brit version.
Like I said, not entirely the same as hopping from time-to-time, but it fits some of your criteria. Great soundtrack, too. Plenty of Hawkwind, T.Rex, etc.