In movies, that used to be The Matrix Trilogy for me. Same with Farscape in TV. But the luster has finally worn off much of the Matrix for me, and I think after this run-through of Farscape I may take 5 or so years off before viewing it again. (Unless they ever find those original film masters and re-do the FX to match for a "super-awesome HD edition".)
Right now I'm between highly anticipated geek releases, and so I'm dipping back into some old favorites in video games. But I've found that the one video game I ALWAYS seem to come back to in these "between seasons" is Neverwinter Nights. So many classes and excellent campaigns (both official and user created) to play with. The potential just seems as limitless as the PnP source material it's based on sometimes! I've played many other video games more than once and a handful more than twice! But "Neverending" Nights doesn't even have a close second for me.
How about you?