A friend of mine actually asked me yesterday if FLCL did indeed have a plot. And even though I know how to explain it, it felt kind of surreal to even do that. Mostly the show is obscure randomness and in the seams are bits of plot, yet more or less the randomness is going to stand out more so the plot doesn't feel all that important. But it's there. It has an actual meaning behind why things are happening, but you wouldn't think that the first time you watch it.
Can't think of a show where there's a decent plot to a story with it all being shadowed enough by everything else in it that it makes talking about said plot feel weird.
EDIT: Also, been watching lately two new anime. Log Horizon, which is on the same lines as .Hack// and SAO taking place in an MMORPG. At first I thought it was only jumping on the bandwagon, but it's pretty good. It sets up its rules nicely and the fight scenes are interesting. What's most interesting is that the main character isn't also the main fighter. He's the guy that comes up with the battle plan. I like smart main characters who aren't cocky. Not as good as SAO, but it's shaping up to possibly come close. The second being Tegami Bachi: Letter Bee. An anime that romanticizes letter delivery to an extreme, but when I was younger the manga really captured me. It's also set in a post apocalyptic world without a sun, but it still has a lot of culture. And you also have giant armored insects that feed off emotions and heart. So... basically they're when SotC Colossi meet Heartless.
"Cogito, ergo es eggo." A.K.A. "I think, therefore you are a waffle."