for starters, might i suggest listening to something besides a greatest hits compilation?
greatest hits compilations are not the way to listen to a band like zeppelin that made at least five stellar albums. do yourself a favor and listen to them in context, the way band intended them to be heard, not the way the record company decided they could make extra money off of the casual fan that only knows a few songs.
as for watching them on dvd, i've owned "song remains the same" for so long now and had it on vhs before that. to be honest with you, after the day the other led zeppelin live dvd came out, i never watched it again. "song remains the same" is kind of a joke contrasted with the newer live double dvd. watch that thing and you may see what people see in zeppelin. you may not too. everyone has different tastes but that one is much more the feel of live zeppelin than "song remains the same" ever will be.
there's my 2 cents plus a couple of dollars more.
"I happen to have perfect situational awareness, Lana. Which cannot be taught, by the way. Like a poet's ... mind for ... to make the perfect words." - Sterling Archer