OreImo started out really strong, but the rest of the season wasn't as amazing as it was from my initial impression. The show has high quality production, and I think that touch is what keeps it worth watching through the whole thing; great animation, nice soundtrack, talented voice cast. The multiple characters have their own quirks to them, and the show reveals different sides of them throughout so they're very memorable by the time you're finished. The TV series is done airing, but there are more episodes of an alternate ending (in true VN fashion) coming out, so while the ending was lackluster, I'm looking forward to a different take on it.
If you're not too keen on otaku culture you might not be able to relate to a lot of the references in the show, but it's not like you can't enjoy it; it's just that you won't appreciate how much of a fan show it is.
Death Note was nice, but it is kinda old news. I mostly prefer the manga to the anime, if only because the anime over-dramatized things, and I'm not just talking about taking a potato chip and eating it.
Katanagatari is a series that just ended recently that I'd recommend. It's got the adventure, action, and fantasy elements of a shounen series with witty dialogue and character interactions to give it some depth. The art style is also one of the most unique styles you'll ever see in anime. Fair warning: each episode is 50 minutes long, though once you get into the show, 50 minutes will seem like nothing.
The Disappearance of Haruhi Suzumiya is amazing. Amazing.