I'd say "I keep all the old shows/podcasts and occasionally re-listen to them " I do listen to the podcasts alot, sometimes over and over again. I usually miss the show live, but it's just because I forget and it's always at about 11:45 when I think "Shit, I missed Adam & Joe!"
currently going through my third time listening to all 70 something xfm shows, i never really stop because then i move on to the old bbc6 music shows and by the time i'm finished with them you kinda forget about the xfm shows right at the start because of the length of time it takes to listen through all of them so the cycle starts again... on show 62 of the xfm shows currently, usually listen to 1/2 a day.
"I have Adam & Joe on continuous loop and listen to nothing else EVER!"
Not quite true, but pretty much. I have quite a lot of old radio recordings, but once I get to my A&J pile I shoot right through them, usually getting through 2 or 3 shows a day. Like Sam said, by the time you've finished them all, the ones at the beginning are fresh to you again. With all my radio .mp3s, it's usually 6 months before I hear the same show again.
I'm usually about two shows behind on the podcast because I normally save them for train journeys. Whenever I'm up to date with the podcasts I'll put some old ones on my mp3 player and have some nostalgic fun. If I'm going to see Adam live then I always make sure I'm up to date because he'll often refer to something, like the fact that the Finnish model woman was at the last Out Of Focus Group (although she'd gone to the bar when he gave a shout out to her).