What's the deal with Seinfeld? I like the idea of a comedy show about nothing, but the few episodes of the show I have seen haven't even managed to elicit a chuckle out of me. I don't understand why it's so universally praised. Same goes for Curb Your Enthusiasm.
I've seen some episodes of The X-Files, but never actually watched it. Same with Buffy and Angel. And Farscape.
Even the unexplained disappearance of a major character hasn't bothered me as they didn't seem to be doing much anyway.
Get used to it.

Quite a few characters in The West Wing disappear to Mandyland, but a few of them were lucky to show up again years later.
I'm curious whether they're able to keep quality for the entire seven series.
Be aware that Sorkin left the show after season 4 with the mother of all cliffhangers, and the writing staff hired to replace him struggled in their attempts to imitate his style. Once those writers stopped trying and focused on their own storylines, the show improved again, but at the cost of being a very different show from what we knew.
I've seen fragmentary episodes of West Wing, which generally convinced me the show wasn't worth my time (it just seemed so damn obnoxiously smug, in an preening, unlikeable way - the same reason I generally avoid anything with Aaron Sorkin's name on it, from The Social Network down to Newsroom).
It's extremely smug, and it has a litany of problems, but damn if I don't love it anyway. It actually reminds me a lot of Star Trek; smug, pretentious, and melodramatic, but with great characters, some great stories, some really thought-provoking episodes, and a genuine warmth to it.
The only one on my original list I feel I must get round to seeing one day is Twin Peaks, which I've heard mixed things about. Mind you, that seems par for course for poor old Lynch
Twin Peaks is great up until they resolve the Laura Palmer murder, after that the show completely loses focus until the excellent series finale, but that ended in a cliffhanger that was never resolved because the show was cancelled. It's definitely worth watching, but it really isn't worth going past the Laura Palmer stuff unless you have a lot of time to spare.