You sound like you've got similar tastes to mine. A lot of the stuff I'm going to list has already been mentioned. Just think of it as an extra endorsement.
Fruits Basket - Honestly one of the funniest anime I've seen. Bit of drama llama at the end, but nothing to get in a twist over.
Lucky Star - Slow start if you don't know what to expect, but too damned cute once it gets going. Stick with it.
Maburaho - Looks like a typical harem anime at first glance, but I really felt for the main character. Surprising amount of depth to the story. Similar to Girls Bravo in a lot of ways.
School Rumble - Watch it or I'll kill ya! Harima Kenji = God. Honestly, this guy actually replaced Sagara Sousuke in my top five favorite characters list.
The Melancholy of Haruhi Suzumiya - I thought for the longest time that this one wasn't going to live up to the hype. I was wrong. It's fun, smart, and every character in it is just LIKEABLE, even the bit characters.
Patlabor - I know, a lot of people reading this list right now are like... "Nani?" Seriously, watch this. It's very old school, but damned funny with great action.
Otoboku - I was very, very pleasantly surprised by this title. I thought it was going to be gimmick anime at first, but the story was surprisingly sweet and it has a really good ending. Plus, it's got one fantastic tsundere character... Mmmm...
Shuffle! - This is the second best harem anime I've ever seen, without a doubt. The director of this series had some serious balls. I won't ruin it, but the main character actually CHOOSES in the end...! And I APPROVED OF HIS CHOICE.
Tenchi Muyo! Ryo-Ohki OAVs and Tenchi GXP! - Everybody knows these, or at least they should. Tenchi was one of the first real harem stories and it's probably still the greatest. EXCELLENT writing, very sophisticated balance between the characters, and the best villain in anime. GXP is pretty awesome too, even if Nabeshin went a little overboard with the directing.
Dual: Parallel Trouble Adventures - Another excellent series by the creator of Tenchi Muyo!. It's one of my all-time favorite mecha anime, too.
Onegai Teacher - Mizuho-sensei... *drool* Um... Sweet story, likeable main characters, cute mascot... A bit teen angsty, but not horribly so.
Ah! My Goddess!! - Classic. Everybody knows this one. It's an old manga, but the anime seasons are pretty new. Different pacing than the manga, but still good.
Midori no Hibi (Midori's Days) - Funny shit. Dateless delinquent wakes up one morning to find that his prized fighting hand has been replaced by a miniature girl. Hilarity ensues...
Maison Ikkoku - Loooong old school anime by Rumiko Takahashi, creator of Ranma 1/2 and Inu Yasha. Don't let that fool you. There's no demons or kung fu pandas in this, just laughs, a very cute girl, and the worst neighbors in history. Great, great romantic comedy. I wish Takahashi-sensei had written more like this one...
Karin - May be a little hard to find since Geneon went kaput half way through the series distribution. Karin's a reject vampire who GIVES blood instead of taking it. Cute girl with horrendous nose bleeds who's trying to keep her family's secret from the rest of the world. Good stuff.
Sayonara Zetsubou Sensei - Story of a suicidal teacher and the class of freaky girls he teaches. One of the funniest damned anime I've watched in a long time. It can't really be described in words. Just see it.
Now THAT'S a list. If you can't find something decent to watch now... I can't help you. If I think of more later, I'll add them. >.>