Another anime i watched a little while ago, from a couple seasons ago, is Ore No Imouto Ga Konna Ni Kawaii Wake Ga Nai, which translates pretty much to "There's No Way My Little Sister Can Be This Cute". I know what you're probably thinking, it's a hentai, you're wrong, mostly. The sister is a female Otaku, and is hiding it from her family, and her brother finds out about it, and helps her meet people with similar interests, and she teaches him about her hobby. I'm horrible at summing up stories, as you can probably tell. The boxes of the eroge are all mostly real life games, some of which i've played, but not all, so it's an added bit of otaku seeing themselves in the characters.
The opening titles, which change for each episode, sometimes hilariously, sometimes subtly, and it's even sort of lapshaded in the show.
A preview video of sorts:
One thing that i find absolutely awesome is that the show sticks with the game theme by having different endings. The series proper has one ending, the 'good ending', then a special with the 'true ending', and another special witch hasn't aired yet, but i'm guessing a 'bad ending'. They even had the choices pop up on screen at the main decision points. Pretty neat.
A video showing the various opening changes, not really any spoilers, but dizzying if you aren't prepared for it.
Basically, this is awesome, it's lighthearted, and pretty damn funny in lots of areas, more so if you are an otaku or 'get' the jokes. It also joins the ranks of Genshiken and Welcome to the N.H.K. as an anime about and for the otaku, both of which are released in the states on DVD already, and worth watching.
Funny thing is how "There's no way my XX can't be this XX" has been a meme in Japan, with several hilarious jokes and images made. ;)